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ducting an admirable free dispensary for the past two years, have enlarged the sphere of their operations,

and developed into a hospital. They have been enBY J. E. L. DAVIS, M. D. , NYACK.

couraged by a munificent donation of valuable land, October 6, 1879, was called to see Mrs. R., æt. 21. much more, to be received at the death of the donor.

on one of our main thoroughfares, with a bequest of as Found her having slight labor pains, and somewhat alarmed at the bleeding, which she termed a show."

A full organization has been effected, and the MediIt was of a bright red character; the patient complain-Chairman and Surgeon; Dr. D. J. McGuire, Ophthal

cal Board organized as follows: Dr. J. G. Gilchrist, ing of nausea and dizziness.

I learned from one of her associates that she, the mologist; Drs. S. F. Pomeroy, J. D. Craig, c. c. patient, had slight hemorrhages, from time to time, Miller, and R. C. Olin, Physicians ; Dr. E. D. Weed,

Resident. previous to this, but, as she was desirous of having miscarriage, did not consult a physician.

We have started out with a fair patronage, and the Also learned that this was her eighth month of promise that in a reasonable time our hospital will i pregnancy.

develope into one of the institutions of the city. She had two children previous to this, and with

Fraternally, each child long and tedious labors.

J. G. GILCHRIST. Upon examination, found the os uteri soft and Detroit, August 8th, 1879. slightly dilatable., laying the above symptoms, I 1. prescribed Ipecacuanhu, and directed her to keep very ,' quiet, hoping she might be delivered at term without į further (litficulty.

RULES FOR SENDING CONSUMPTIVES TO TRAVEL. Oetober 7, found her comparatively comfortable; an The following rules are those laid down by Dr. James occasional slight pain and no hemorrhage.

Edward Pollock in a recent lecture : October 8, A.; M., labor pains frequent, but not

1. Never permit any patient to travel who is not in strong or lasting very long; some hemorrhage. By the quiescent stage of disease, or wbo, in other words, 1. examinution, found the os uteri soft and easily dilata- is feverish, with high evening temperature, and the ble. The placenta presenting itself in the form of a

physical signs and conditions already described to you, soft spongy mass, I concluded to partially separate the indicating the continuous form of phthisis. Observe ! placenta, finding, if possible, the side to which it was

this rule, and you will be successful; break it, and the least attached. This, I soon determined, was on your patient and his friends will not thank you. the left side, to the extent of about an inch and a half.

2. None of the secondary complications should be I entirely separated it on that side; te hemorrhage present; as, continuous or frequent diarrhæ, serious not being very profuse, and easily controlled,

gastric disorder, or laryngeal irritation. I now found an arm presentation, which, by con

3. Chiropic single cavity, with retraction of walls, joined manipulation, was changed to the cephalic,

accomplished or proceeding, is favorable for removal I then made a slight picture in the membrane, to a dry, bracing locality, if the bæmophysical element thinking I was doing a very good thing, but the dis- is wanting in the case. charge of liquor ismnii was very copious, and although

4. That form of disease described as diffuseá

deposit the presentation was good and the haemorrhage slight, in one lung, without much dullness or signs of massing yet there seemed to be atony of the uterus, from too of dise-se, with pretty large chest, and with more sudden relief.

moderate emaciation, generally does well on 'A' sea She did not have another pain for nearly twenty vocase. hours; then they began to come again, spasmodically.

5. A first stage case, already chronic, does best for I now administered scale corn., the only result being traveling about, with trequent change of residence. that the pains were more frequent, not strony or last- The complication with bronchitis or asthma is geneing long. The hand again seemed to be presenting mully much benefited by change and the head retracting. I concluded to turn and de

16. Persons ought not to travel at all with feverish liver at once, for my patient was growing weaker.

pisymptoms, withi secoudary complications, with a large The liquor, amnii las nearly al. escaped, and my amount of local disease in any stage; with both lungs endeavors, only resulted in bringing down the other Misenser, with poor: digestion anii greatly lowered nu

i trilion ; or in such a stale of weakness or emaciation arm, Join This is returned with some difficulty, and the headly as 10 require home comforts, peculiar brds or chairs, or again brought down, I then applied the forceps and Virieties of invalid cookery. --Medical urid Surgical Redelivered the patient. The child was still born; the parter)011 mother is making a rapid recovery. Consi ierable !:)**'*} li feian li force was necessary in the delivery of the child; the PICRATE OF AMMONIA IN WHOOPING COUGH-WAND luuad, arms and shoulders w were large; other parts of DIPHTUERIA. - Dr. Z S. Dellenbangl reports, ten

the body s vall. There was a sliglit' rupture of the or twelve cases of whooping cough he has treated perinetin, thit, with Culemanla dressing, heáleit very withi pierate of airmonia with the most satisfactory re# 1,'

sults. “Indeed, some of the cases were cured in the mm, D TOT

marvelously short time of from twenty-four to seventy

two hours.” In view of this experience, together with . ri gome tifteen or twenty cases repomed by him within

the past few days, Dr. Dellenbaugh thinks he can 1'' olid B 11, site! ?). 1, 101 most sufely affirm that, if properly administered, the TN HOMEOPATHIC HOSPITAL IN DETROIT. pierate of ammonia is a specific for the cure it' wlioop

ing cough. He gives to babies from one-sixteenth to * MESSRS. EDITORS :-It may interest you, and your, one twelfth grain, and to children from one-tweifth to *** many readers, to learn that this eminently conservativerone eightly grain, every three hours! In one sonyie of 1-1 eity has at last: Rouised ilselt sufficiently to comprehend, diphtheria; he has also used pierate of ammonia us a

that homeopathy is an established tact. With ample gargle (gr.viij to oj), and by atomization. The solubospital privileges for the elect, our practitioners have tion of picrate produced a yellowisli sta iming of the

hitherto been without representatation on any of the parts in such a way that he was inclined to believe a du medical boards of any of our numerous charities. A destruction of the microodcviensuod, and a speedy Bitlle bånd' of self-denying iwomen who Alaveibeen con- ficure of the disease was the resulta , VT18 sites



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N. Y. OPHTHALMIC HOSPITAL. Month ending PROVINGS, IN THE AMERICAN INSTITUTE OF HOMEO-488; resident, 26; average daily, 126; largest

, 182.

Sept. 30, 1879: Prescriptions, 3.276; new patients, PATHY,-Special subject to be reported on and dis

J. H. BUFFUM, M.D., Resident Surgeon. cussed at the meeting in Milwaukee, June, 1880: “ The

WANTED -A Junior Resident for the Brooklyn Limits of Drug Attenuation and of Medicinal Power Homeopathic Hospital and Dispensary. Apply either in Homeopathic Posology:"

in person or by letter to to S. E. Stiles, M.D., Resident I. The proofs of drug presence and power in attenu. Physician, 109 Cumberland Street, or J. G. Atkinson, ations fabove the sixth decimal: (a). As furnished by M.D., Supt. of Dispensary, 304 Adelphi Street, Brookthe tests of chemistry-W. L. Breyfogle, M.D. ; (). A's lyn. furnished by the spectroscope and microscope--C. | Wesselhoeft, i D., J. Edwards Smith, M, D. ; (c). As

VOMITING IN PREGNANCY.-Dr. J. F. Baldwin, of furnished by the tests of physiology-T. F? Allen, Columbus, O., has found Copeman's method ” of M. D., Lewis Sherman, M.ʻD.; (d). As furnished by thoroughly dilating the external os and cervical canal analogy from the field of impalpable morbific agencies with the finger successful in three desperate cases of -J. P. Dake, M. DI

vomiting. II. The proofs of medicinal presence and efficacy in attenuations above the sixth decimal: (a). As tur

REMOVALS.--Dr. A. R. Thomas, to 1,733 Chestnut nished by the tests of clinical experience, in the use of Street, Phila : Dr. E. B. Britton, to 30 South Broadattenuations, ranging from the sixth to the fifteenth way, Baltimore; Dr. Mary W. Noxon, to 531 Fifth decimal-J. F. Cooper, M. D.; (). As furnished by Avenue, N. Y ; Dr. Clara C. Plimpton, to Nashville, clinical experience, in the use of attenuations, ranging Tenn. Dr. Thos Wildes to 35 West 31st Street, N.Y. from the fifteenth to the thirtieth decimal-A. C. Cow. Dr St. Clair Smith to 11 East 38th Street, N. Y: perthwaite, M. D. ; (c). As furnished by clinical experience, in the use of attenuations above the thirtieth

DANGER OF OPIUM IN CHRONIC BRIGHT'S DISEASE. decimal-C. H. Lawton, M. D.; H. M. Paine, M. D.

- The possibly dangerous effect of even small doses of At the last meeting of the Institute this Bureau re- morphia in chronic Bright's disease, although alluded ported upon the “ History, Methods and means of to by several writers of authority, is not so widely and Drug Attenuation,” in an exhaustive manner. The thoroughly known as it should be by the profession. reports of the current year, passing from the domain Intolerance of this drug is one of the peculiarities of of Pharmacy somewhat into that of Posology, will the disease; doses so small as to be looked upon as safe complete a work of vast importance for Homeopathy. under any circumstances will sometimes have a poison

The Bureau will be pleased to receive items of ous effect. -- Phil. Medical imes. information and experimental aid from members of GRAAFIAN VESICLE DURING PREGNANCY.-Dr. Slav. the profession, and, also, from scientific persons out- insky reports the case of a woman, aged 24 years, who side, who may be interested in any division of our died in the third month of gestation, and the post mortem subject.

J. P. DAKE, M. D., showed ovarian follicles which were on the point of NASHVILLE, TENN.


bursting, as well as recent corpora lutea. This con

firms the opinion enunciated by the late Prof. Charles AT LAST.- A question of nearly ten years' standing D. Meigs, that the development of the graatian follicles has at last been disposed of in Boston. It is the continued during pregnancy.-- Med. Central Zeitung. woman question which has so long obtruded itself into the deliberations of the State Viedical society. At-i

Dr. S. H. Quint of the New Jersey Homeopathic tempts have repeatedly been made to secure the Medical Society has been appointed Medical Superin. admission of women to membership, but conservatism, tendent of the Camden Co. Insane Asylum at Blackalways of a rigid type in this organization, turned woodtown. The asylum has about seventy patients. coldly away each time from the proposed innovation. Year by year a progressive spirit has gained ground

HEALTH BOARD, KENTUCKY. --A petition signed by among the ranks of younger members, and at a recent eighty of the most prominent citizens of Louisville, meeting of the Council the Board of Censors were very for the appointment of a homeopathic member of the quietly directed to examine all female applicants for board has been refused by Gov. Blackburn on the admission. The young members are very happy over ground that a homeopathic physician is not “regtheir victory; the older ones accept it with what good ular.” The proper wisdom of the governor's decision nature they can, but insist that it does not concern will be more apparent when it is understood that it the public, and the less that is said about it the better comes from an allopathic physician. It is believed that very few female members will result from this decision.

WHAT IS A TEAR ?-Rev. Dr. Talmage says in one Messrs. Editors :

of his sermons, "if you should ask a chemist what a In Guernsey's Obstetrics, p. 979,“ Glossary,” we

tear is he would tell you it is composed of salt and read :

lime and has other component parts, but he would Cornea-Horney, transparent coat of front part of miss the chief ingredients : the acid of a soured life, eye-lid.”

the viper's sting of a bitter memory, the payment of a The authority for this bit of descriptive anatomy is broken heart...

I will tell you what a tear is. It is not given.

agony in solution, We should think this “ Glossary” might be omitted Dr. J. G. Gilchrist is preparing a work on Surgery, from the next edition as supertiuous, CRITIQUE. to be issued in four volumes, making in all over 2,000

pp. PILOCARPIN IN ALBUMINURIA.-Dr. T. G. Thomas Bros., covers Surgical Therapeutics and Institutes of

The first volume, about to be issued by Duncan regards it as a serious error when a physician thinks Surgery; the second will cover Surgical Emergencies it necessary to produce premature labor in every case and Accidents; the third, which will really be the first, of albuminuria. In the treatment of these cases he Surgical Principles and Minor Surgeryli the fourth, regards it as important to keep up the excessive action

Surgical Operations. of the skin, and for that purpose pilocarpin was suggested as a most reliable diaphoretic. Prof. Barker, Dr, Bukk G. Carleton has been appointed Demonon the contrary, says in the majority of cases in which strator of Anatomy in the N. Y. Hom. Med. College. he has seen this drug used the patient has died.

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Of Medicine, Surgery, and the Collateral Sciences.



No. 9.


ber of persons, such as soldiers, students, police, etc., and found, among 1,154 persons, 56 color blind; i. e., 5.6 per cent., or one color-blind among 17.7 persons.

Wilson used tinted papers for testing, and depended THE COLOR-SENSE AND COLOR-BLIND

upon the name of the color given to the pigment by NESS.

the person being examined; only those who hesitated in distinguishing red and green were challenged and

tested according to the method of Seebeck. AccordBY ALFRED WANSTALL, M.D, BALTIMORE,

ing to Wilson, the color blind must renounce painting, weaving, tailoring, chemistry, botany, geology, medi

cine, etc., and especially, their employment on rail(Written for the Bnreau of Miscellany, including Anatomy, roads and in the marine is dangerous, and may occaChemistry and Physiology, of the Homeopathic Medical tociety sion loss of life. Wilson did not content himself with of the State of Maryland.)

calling attention to these dangers alone, but he also Personally, except in a very limited degree, I possess endeavored to establish rules for prevention, and prono practical knowledge of this subject. For the past posed that the colored signals in use be retained, and two years the scientific world has been so agitated all color blind persons be excluded from the service; or about it, and the results of the investigations have that all persons be retained in the service without become so numerous and interesting, that I feel no hes- regard to their color-sense, and the signals be changed. itation in bringing it before this society even at this The single practical result given by Wilson as the somewhat lale day.

result of his work is the decree of the Great Northern Color-blindness possesses a history. The first offi- Central Railway Company that their collective emcially known case was related by Joseph Huddart, of ployés must possess a normal color sense before their London, in a letter to Joseph Priestly, in January, admission to the service. 1777, now more than a hundred years ago. It referred Dr. A Favre, of Lyons, France, consulting physician to a shoemaker by the name of Harris, of Cumberland, of the Paris- Lyon-Nediterranean Railway, has for a Eng., and his brother, the captain of a merchant long time busied himself with the practical side of the vessel.

question. He examined for color blindness the em. The first accurately described case is that of John ployés of the above railroad, also soldiers, sailors, and Dalton, the celebrated English chemist and physicist. scholars. The work of Dr. Favre has called forth two Red blind himself, he studied this defect on his own new ideas. He directs special attention to acquired person, and published in 1794 an exact description of color blindness, which, according to him, is of toler, it. After him color blindness received the name Dal- ably frequent occurrence, and asserts that congenital tonismus. People were astonished to hear, from the color-blindness is not incurable, and can be remedied communication of this celebrated man, that to him the by the systematic and continued practice of the colorred of the rose and the blue of the sky appeared as the sense, same color, and that no distinction existed between Still later, this subject has been much discussed in the bright red of the sealing wax and the green of the Germany, Sweden, and other European countries by turf.

Stilling, Holingrew, Magnus, Cohen, Daae, Donders, Seebeck was the first to examine a relatively large and others. number of persons, and compare them with one

THEORY. It is well known that a luminous body another. As early as 1837 he had collected twelve sets the smallest particles of the surrounding ether in cases of complete color-blindness, and mentioned, wave like vibrations, which extend from it in all direcbesides, a small number of more or less incomplete tions. cases which formed the transition to typical color- When these vibrations come in contact with our blindness. He saw already how deceivable and un sensory organs, whether in a direct line from the certain it was to estimate the nature of color-blindness luminous body, or reflected by another body, they from the name of the color wbich the color blind produce certain changes which are interpreted in give to the object. He used principally tinted papers, our nervous centres into definite sensations. If they about three hundred in number, and tested by como come in contact with our skin, they are interpreted parison.

as heat; if with our retina, we experience them as George Wilson, professor of technology in the Uni- light. so it is our brain which, as the result of cer. versity of Edinburg, was the first to study color-blind- tain changes in our sensory organs, generates light ness in its relation to the different occupations of life, and heat; although we designate the external origin and to call attention to the danger of employing color by these names, and say that light and heat rays problind persons in the railroad service and in the marine, ceed from the glowing body, yet we must distinguish as well as in other positions where colored signals light and heat in an objective sense—which are one must be recognized. "Wilson examined a great num-and the same thing, namely, vibrations of ether—from

light and heat in a subjective sense, which are sensa. centres. By mingling two pigments, white light is tions of a totally different nature,

twice subjected to the process of absorption, and If all vibrations of ether were of a similar nature, or what remains over is the colored light reflected from if all the elements of our optic apparatus reached in the painted surfaces; while, on the other hand, the the same way to all vibrations of ether, we would process of mixing colored light is one of addition. scarcely appreciate difforent kinds of light : every This will be sufficient to show why our color sensaspecific irritation of our optic apparatus would produce tions cannot be studied with the palette. à sensation of light whose intensity would depend The following is the color theory of Herring: Red, upon the strength of the illumination, but not its green, yellow, and blue are the simple or principal nature, A quantitative difference could be appreci- colors. Pure red and pure green (subjectively) mixed ated, but not a qualitative ; in other words, differ nt give a colorless sensation of gray; likewise, pure yelkinds of light, i. e., colors. Physics teach that the vi. low and pure blue. Pure red, on the one hand, forms brations of ether are of differ nt kinds, and that they all conceivable tones of color through yellowish red are distinguished from one another by the rapidity of and blue red, in which we have lhe sensation of both the vibrations, and the length of the waves. It is colors, or recognize them; pure green, on the other owing, to these differences that we appreciate differ- hand, forms all conceivable tones of color through ences in quality, i. e., colors.

yellowish green and blue green, with which both All quality of light must necessarily depend upon a colors are likewise recognizable. Herring indicates difference of function of the elements of our optic red and green, not as complementary, but as antagoapparatus. There are two possibilities: Our optic nistic colors; they work against or destroy each other apparatus possesses only one kind of elements, and in the act of exciting the sensation of color, as is also these are set in different functional activity by the the case with yellow and blue. different kinds of vibrations; or there exists in the Our sight substance is composed of three different retina or brain different terminal apparatus, of which kinds of matter, namely: 1. The substance for the each always reacts in the same way, while they are sensations from black to white; 2. The substance for different from each other.

the sensations from red to green; and 3. The substance The principle upon which the sensation of quality for the sensations from yellow to blue; and are called of light—ie, color-is explained, is as follows: If one the black-white, the red-green, and the yellow-blue element is excited alone, or if all are simultaneously substances. No color or tone of color can be experi. excited, but one more than the others, we experience enced in complete purity; and, also, the black-white the excitation of this one element as quality of light, substance is always affected by all the objective colors. as colored light, or as color, and call primitive or if the sight substance is affected by objective yellow fundamental color that which corresponds to the ele- and blue in such proportions that the color sensations ment excited. If two elements are excited, or if they destroy each other, there remains of them their action are preferably excited, we see colored light, but in a on the black and white substance, and the re

resulting color which corresponds to the mixed color of the sensation is a colorless gray. The same is true of red two elements excited. This principle permits of the and green. From the action of the collective rays of assumption of many fundamental elements and primi- the spectrum, the sensations red and green, yellow tive colors. Likewise, from the simultaneous and and blue, are lost, and there remains only the action similarly strong excitation of all the elements no color on the black white substance. sensation can originate. We then see light in gene- The red-green substance is affected, on the one ral, in contradistinction to absence of light, i. e., dark- band, from the most external red of the spectrum to

pure yellow; on the other hand, from greenish yellow It is evident that when one element is principally to blue; and again, by the red contained in the violet excited, while the others are excited to a less degree, of the spectrum; in pure yellow and in pure blue, not the sensation of the specific quality of light will be at all; in pure yellow, certainly not, because the action weaker accordingly as the excitation of the other of red and the antagonistic action of green destroy elements is stronger, because the sensory effect of the each other; in complete blue not, because the action irritation corresponds to a mixing of colorless or white upon the green-red substance occurs with the opposite light with the specific color of the principally excited action of the violet upon the green-red substance. element.

The yellow-blue substance is.excited, however, from The approximate representation of all colors can be red to green, and from blue green to the end of the produced by the use of three pigments or colored spectrum. Aubert. Physiologische Optik. Farben. powders: red, yellow, and blue; red and yellow form- Sinro. Graefe und Saemisch, Bd. II.) ing the different shades of orange and orange-yellow, According to the above theory, color blindness must blue and yellow giving a variety of shades of green, consist of an absence of or want of function of one or blue and red all the purple and violet hues. These the other color-seeing substances; and color-blind perfacts furnished the foundation for the theory of the sons must be either red-green or yellow-blue, or, finally, three primary colors, of which David Brewster was totally color-blind. With red-green blindness the color the most ardent defender. He maintained that there system consists only of yellow and blue. The specare three fundamental kinds of light-red, yellow, and trum appears only in these two colors. Colored stuffs blue-by the mixture of which all kinds of colored appear yellow, blue, or gray, according to the quantity light can be produced, as is the case with the pig of the different kinds of reflected light. The spectrum ments.

is, in most cases, of normal length; in single cases, This theory has been shown to be entirely without much shortened. foundation. The results of mixing different kinds of Blue-yellow blindness. The color system consists light, by Maxwell's disks, is entirely fatal to the theory only of red and green. The spectrum appears only in of Brewster. Color is a subjective sensation, and its these two colors. Colored stuffs appear green, red, or laws can be studied only by considering the subjective gray, according to the relative quantities of the resensations produced by mixing different kinds of light. Alected kinds of light. The spectrum can be much The color of any object is due to its property of ab- shoriened, and it can be of normal length. sorbing some kinds of light and reflecting others. We In comparison with red-green blindness, blue yellow can see why the result of physically mixing a yellow blindness is very rare. Total color-blindness is relaand a green pigment may be entirely different from tively very rare, and little understood. They see only mixing yellow and green light reflected from two black, white, and gray. surfaces, as is done in the case of Maxwell's disks, Early in the present century Thomas Young first when the mixing or union takes place in the nervous propounded the theory of three fundamental colors.


About 1850 this theory was reviewed and advo- violet blindness; and b, a lower degree, which may be cated by Helmholtz, since which time it has received indicated as a weak color sense. many adherents, and is known as the Young-Helmholtz Stilling classifies color blindness, accordingly, as hypothesis. It assumes three fundamental colors; red, those color sensations which are indicated as simple, green, and violet, and, accordingly, three correspond are absent, and in harmony with the theory of Her ing elements in the optic apparatus. If the red sensi. ring, of four principal or simple sensations. Since tive elements are alone excited, or more than the each two of these stand in a polar relation as positive others, we experience red, and so for the others. The and negative, so, when one color fails with a color different vibrations of ether excite the different ele. blind person, the other antagonistic color must also ments in a different degree, but always so that all are fril. Either the collective color sensations fail, or the set in a certain degree of excitement Homogeneous sensations of red and green, or yellow and blue, fail at red light irritates, from the outer end of the spectrum the same time. to its side of orange, the red sensitive elements in

1. Color blindness is divided into a high degree; much less the green, and still less the

a. Red-green blindness, violet. In this way the sensation of red originates,

b. Blue-yellow which goes more and more into orange as the irritation

c. Total color of the green sensitive elements increases. Homogene. ous yellow irritates strongly, and, in almost the same 2. Decreased color sensitiveness is divided into degree, the red and green sensitive elements, while it

a. That for red-green. affects the violet sensitive elements only very weakly.

b. That for blue yellow. On this account the sensation of yellow is a combina

c. Total. tion of red and green, Green light irritates the green sensitive elements strongly, the two others very weakly These different kinds of decreased sensibility of the and in almost the same degree. Hence the sensation color sense are not sharply separated. Not seldom of green. Homogeneous blue irritates tolerably strong, true blindness for two antagonistic colors is united and in almost the same degree, the green and violet with a decreased sensibility for the two others, forming sensitive elements; but the red in a less degree. Hence a transition between partial and total color blindness. the sensation of blue is a mixture of green and violet. Color blind persons possess a great sensitiveness Violet light affects the violet sensitive elements ac- toward light effects, which compensates them in some tively, but the two others less. Hence the sensation degree for ubeir loss of color effects. It enables them of violet.

to experience fine and delicate sbades of light when & According to this theory, color blindness must con. color-seeing eye would remark nothing. They also sist of red, green, violet, or total color blindness, ac. understand how to make their fine power of distinction cording as one, the other, or all of the color sensitive for differences in ligbt of practical value. It enables elements are absent, or are deficient in functional them to distinguish colors from one another, which, activity,

on account of their color blindness, seem alike. They Red blindness originates from the absence of or want discover that colors, wbich to them talsely appear idenof functional activity of the red sensitive elements. tical, do not possess a like amount of light, and they The red blind possess two fundamental colors, namely, use this difference in the amount of light to distinguish green and violet. To the red blind, spectral red ap. color tones from each other. This power is much depears as a saturated dark green; yellow, as a lighi veloped by practice. Magnus mentions the case of a saturated green; green, as a light but whitish grada- red-blind locomotive engineer who understood so well tion, of the same color as red and yellow; blue, as blue; how to hide his color blindness, that, in a service of and violet, as violet or dark blue,

ten years, he did not once mistake the red signal, por Green blindness consists in the absence of or want confound it with the green, and was supposed by his of functional activity of the green sensitive elements. superiors, on this account, to be normal sighted. His The green blind possess two fundamental colors, viz.: defect was first brought to light by the obligatory exred and violet. The green blind see the spectral red amination of the color sense of the railroad employés. as a dark but much saturated red; yellow, as a light Magnus frequently convinced himself that this man red; green, as white or gray: blue, as a color similar to did not confound the red and green signals, in spite of the indigo; and violet, as a much saturated violet. the fact that the examination of his color sepse showed

Violet blindness consists in the absence of or want him to be in a high degree red-blind. He afterward of functional activity of the violet sensitive elements. gave this author to understand that he was aware of The violet blind possess two fundamental colors, red his color blindness for a long time, and in distivguishand green. They see the spectral red as red; yellow, ing between the red and green signals, he had been as white or gray, green, as blue green; blue, as green; helped only by the amount of light possessed by the and violet, as dark green.

two colors. Magnus also relates an interesting case of

a red-blind painter's apprentice, who had been taught CLASSIFICATION OF COLOR-BLINDNESS.

by a master for three years, without the master having Holmgren classifies color blindness as follows, in This individual had been able to strike the distinction

any suspicion of the color blindness of bis assistant. harmony with the color theory of young Helmholtz: I. Total color blindness; where the ability to see sensations of light effects. He was so agitated by his

between the different colors only by his sharpened colors is totally wanting, and where the sense of sight condition, and bis anxiety that he would finally comis able to distinguish the difference between light and mit an error so frightened him, that he confessed his darkness, with their different grades of intensity.

failing, and gave up his vocation as a painter. II. Partial color blindness; where the ability to dis- The opinion of Dr. Favre, the French railroad physitinguish definite tones of color, not all, fails. It is di- cian, that color blindness can be removed by a long vided into–1. Complete or typical color blindness; and systematic practice of the color sense, bas not where one of the three fundamental color sensations, been confirmed by experience; and, indeed, the evii. e., one of the three color sensitive organs, fails. This dence is that the condition of the congenitally colorgroup includes three kinds, viz.: a, red blindness, b, blind canuot be improved. This is clearly evinced by green blindness, c, violet blindness. 2. Incomplete numerous cases of color-blind individuals who, through color blindness; where one or all three of the elements long years of practice, were never able in any way to are weaker in irritability or number than the normal improve their condition. For example, the case of color sense. This group includes, a, a higher degree, Harris, the shoemaker, and the celebraicd John Dalton. which can be indicated as incomplete red, green, and Harris was aware of bis defect from his fourth year,

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