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WHEREAS absolute war necessity and shortage of wheat for export has required that, in the exchange milling of his own wheat, the farmer be restricted to a supply of flour equal to his household needs and those of his farm employees for 30 days; and

WHEREAS the present crop prospect seems to make this necessity less acute, be it

Resolved, That the Food Administration be requested to remove this restriction as early as conditions will allow.

12. The committee was of the opinion that groundrock phosphate and acid phosphate should have the same freight classification as agricultural lime, taking an increased freight rate of one cent a hundred pounds, instead of an increase of 25 per cent., as applied to general commodities, and it was directed that request be made to the Director General of Railroads that the desired classification be granted.

13 Resolutions were passed by the committee favoring:

(1) Regulation of the use of mill feeds by the mixers of proprietary feeds, so as to secure to the dairyman the benefits of the efforts of the Food Administration to lower the price of mill feeds.

(3) Equitable distribution of mill feeds. (4) Use of sugar substitutes in ice cream manufactories.

(5) The disallowance of sugar to manufacturers of ice cream failing to comply with reasonable standards of butter fat and solids not fat.

(6) Purchase of dairy products by Army and Navy.

(7) Expression of appreciation to the Food Administration for the publicity given to the economic value of milk.

(8) Recommendation to the government to extend the standardization of dairy and other agricultural products.

(9) Commendation to the market report service by the Bureau of Markets.

The subcommittee on dairy products presented to the tariff department of the Railroad Administration an explanation of the

hardship upon the small shipper of milk and cream, because of the minimum charge of 50 cents on any individual shipment.

The regulation was promptly modified so as to nullify the application of a minimum charge.

Some years ago I repeated Sir Astley Cooper's old experiment of ligating permanently both common carotid and both vertebral arteries close to their origin in dogs. The ex

(2) Regulation of the manufactories of periments were done aseptically and the animixed feeds.

mals allowed to live. The chemical analyses of the brains of these animals were published by Waldemar Kock and S. A. Mann.2 The general results of the ligation were similar in all essential respects to those noted by Leonard Hill. Hill remarks that in one dog, there was preliminary acceleration of the respiration following the ligation of the four arteries.

I noticed respiratory disturbances in some dogs, and one in particular attracted my at

SPECIAL ARTICLES

THE RELATION OF THE RATE OF BLOOD FLOW
THROUGH THE MEDULLA OBLONGATA
TO THE AMPLITUDE AND FREQUENCY

OF RESPIRATORY MOVEMENTS

ALTHOUGH the relation to respiratory movements of the changing concentrations of carbon dioxide in the blood, and of afferent nerve impulses from the lungs to the medulla oblongata has long been recognized, a third factor entering into the equation, i. e., the rate of blood flow through the medulla oblongata, has received but little consideration. Haldane1 mentions the rate of blood flow as one of the factors, but the emphasis, as is natural in pathology, is placed mainly on the general disturbances of the circulation.

1Text Book of General Pathology," edited by M. S. Pembrey and James Ritchie, London and New York, 1913, chapter on Respiration; Organism and Environment as Illustrated by the Physiology of Breathing, New Haven, 1917, pp. 5-6.

""

2 Mott's Archives of Neurology and Psychiatry from the Pathological Laboratory of the London County Asylums," London, 1909, IV., pp. 211-12; Studies from the Rockefeller Institute for Medical Research, X., 1910, p. 38 of the reprint.

3"Physiology and Pathology of the Cerebral Circulation," London, 1896, p. 123.

tention. When lying quietly at rest, there was no apparent change in the respiration. No graphic records or measurements of the minute volume were taken. But when the dog was urged to rise and walk about, it at once began to pant violently. On lying down again, the panting ceased. Other dogs with normal cerebral circulation did not pant except after much greater exertion.

Hill states that none of his dogs died after ligation of the four cerebral arteries, but he does not mention the age of his dogs. I have found that vigorous, full-grown dogs survive the ligation indefinitely, but half-grown pups and old dogs usually succumb within twentyfour hours. I have seen half-grown pups lie unconscious for several hours, sometimes panting violently, and sometimes making ineffectual movements of locomotion with the fore limbs. Attempts to rouse them from this state were unsuccessful, and they were usually found dead the next morning.

Hill remarks that there must be a certain blood pressure resulting in the flow of a certain amount of blood through the medulla oblongata in order to provoke respiration. My experience tends to confirm Hill's conclusion. It is a striking thing to see an animal with failing respiration at a low blood pressure improve rapidly when the pressure is artificially increased.

In the dogs with restricted cerebral circulation, there was no apparent deficiency in the rest of the systemic circulation in those which recovered. Nor is there any reason to suppose that there was any change in the blood which would decrease its power of carrying either oxygen or carbon dioxide. It does not seem improbable that, in the dog with the marked respiratory disturbance, one would have found a somewhat greater concentration of oxygen and a somewhat lower concentration of carbon dioxide in the blood than in dogs with normal circulation. The condition in the medullary center itself, in which carbon dioxide might tend to accumulate in somewhat greater concentration than usual, would seem sufficient to account for the dyspnea on moving about. A lower concentration of carbon dioxide in the

blood would be the natural result of the forced respiration. In cases of shock resulting from abdominal wounds on the battle field, in which there was no deficiency of the systemic circulation prior to the wound, it does not seem necessary to assume the production of any large quantities of acid in the body to account for the lower concentration of carbon dioxide in the blood of such patients. It seems sufficient to suppose that, as the systemic blood pressure falls progressively lower, there would be a deficient blood supply to the respiratory mechanism in the medulla oblongata. The natural result would be an increase in the volume of respiration, and a decrease in the concentration of carbon dioxide in the blood. This would not in itself be a sufficient reason for postulating acidosis as a causative factor in the early stages of shock. Whatever acid might accumulate in the tissues might result, as Haldane suggests, from the deficient supply of oxygen to the tissues.

F. H. PIKE

THE DEPARTMENT OF PHYSIOLOGY, COLUMBIA UNIVERSITY

ON THE HYDROLYSIS OF PROTEINS IN THE
PRESENCE OF EXTRANEOUS MATERIALS
AND ON THE ORIGIN AND NATURE
OF THE "HUMIN" OF A PROTEIN
HYDROLYSATE

IN a recent paper McHargue1 attempts to show that the nitrogen distribution of casein is not appreciably altered when hydrolyzed in the presence of five times its weight of starch providing that the hydrolysis is continued for only 12-15 hours. McHargue reaches a conclusion which is decidedly at variance with that reached by myself and by Hart and seriously vitiates the nitrogen distributions of a Van Slyke analysis and he explains the difference in the findings by his shorter hydrolysis. However, he makes several astonishing 1 J. S. McHargue, J. Agr. Res., Vol. 12, pp. 1-7 (1918).

2 R. A. Gortner, J. Biol. Chem., Vol. 26, pp. 177204 (1916).

Sure, i. e., that the presence of carbohydrates 8 E. B. Hart and B. Sure, J. Biol. Chem., Vol. 28, pp. 241-49 (1916).

4 Loc. cit.

statements in his paper to which it seems worthy of calling attention.

He states:1

In the footings of the different analyses it will be noted that the 12-hour digestions give footings more than 2.5 per cent. over 100. In the 15-hour digestion the footing is good, while in the 24- and 48-hour digestions the footings are 2.75 per cent. less than 100, thus indicating that the 12-hour ex

least reactive of the chemical substances ordinarily met with, resembling in much of its behavior ordinary bone black. The humin of protein hydrolysis is a black, granular, noncrystalline substance, insoluble in the ordinary organic solvents, somewhat soluble in alkalis from which solution it is precipitated again by acids, and, in short, the true humin of protein hydrolysis agrees in every respect as regards

periments were probably not completely hydro- physical properties with the material which

McHargue discards and refuses to call humin.

lyzed; whereas the 15-hour digestion was sufficient to bring about complete hydrolysis and the 24- and 48-hour experiments were over-digested to the extent that nitrogen was lost.

Then again, the nitrogen of the fraction which he discards certainly belonged to the original casein, for his starch was practically nitrogen-free. How then can he claim that hydrolysis in the presence of starch does not alter the nitrogen distribution? This nitrogen which he discards belonged to the original protein molecule and should be included in the starch hydrolysates if it is included in the original casein analysis with which the starch hydrolysates are compared.

As I have shown previously (2), hydrolysis in the presence of carbohydrates causes a very considerable increase in the insoluble humin fraction and this increase is due to both chemical and physical causes. The nitrogen in the true humin of a protein hydrolysate has its origin almost wholly in the tryptophane molecule and the reaction by which it is formed appears to be the condensation of tryptophane with an aldehyde or ketone. When carbohydrates are present the acid causes the formation of furfural which condenses with the tryptophane to form a "humin." However, furfural itself has the peculiar property of polymerizing (?), in the presence of 20 per cent. hydrochloric acid, to a black insoluble substance with the result that a large mass of porous black material is formed in the hythrough physical means, retains a very condrolysate and this material, presumably siderable amount of non-tryptophane nitrogen which normally would not appear in the humin fraction. Perhaps these latter forms of nitrogen would not be present in the black mass formed from the furfural in as great a quan

One can but wonder where he secured such reasoning, or it is needless to point out that not more than 100 per cent. of the original nitrogen can be present in a protein hydrolysate even if complete hydrolysis has not taken place and the literature of proteins shows that no nitrogen is lost by overhydrolysis. Gortner and Holm recently hydrolyzed fibrin for 6 weeks and obtained a recovery of 99 per cent., while 201 hours' hydrolysis showed a recovery of 100.7 per cent. the figures being, in both instances, within the experimental error of the analyses.

However, his most astounding conclusion is that the nitrogen in the insoluble residue obtained from the casein starch digestion "is in an inert form and its estimation should not be included in the humin determination," with the result that he ignored the presence of nitrogen in this fraction in calculating his nitrogen distribution. Unfortunately he does not tell us how much nitrogen remained in this fraction so that we can not recalculate his data, and as a result all of his laborious analyses are worthless. I use the word "astounding" in the above sentence advisedly, for in all of the protein literature I can find no refer

ence to the black humin of protein hydrolysis

which does not define it as insoluble, unreactive and inert, and any one who has studied its properties knows well that it is one of the

4 R. A. Gortner and G. E. Holm, J. Amer. Chem. Soc., Vol. 39, pp. 2736-2745 (1917).

* He does give the per cent. of nitrogen in the black material but not the weight of the black material.

R. A. Gortner and G. E. Holm, J. Amer. Chem. Soc., Vol. 39, pp. 2477-2501 (1917).

tity in a twelve-hour hydrolysate as in a fortyeight-hour hydrolysate, but there is no question but that a part of the tryptophane nitrogen would be in this fraction.

It is of interest to note that McHargue obtained no "insoluble humin" for the twelvehour hydrolysate of casein to which no carbohydrate had been added, and that his "histidine" fraction is in excess of that reported by other analysts. This observation accords beautifully with the idea of Gortner and Holm that an aldehyde or ketone must be present to cause insoluble humin formation from tryptophane and that when insufficient aldehyde is present and the hydrolysis is not sufficiently prolonged the tryptophane will be (in part) precipitated by phosphotungstic acid and augment the "histidine" fraction [cf. Gortner and Holm'].

However, all of this discussion, pertinent as it may be, would be trivial were it not for the fact that other workers may be led to accept McHargue's conclusions and thus cause a further waste of money and energy in pursuing an illusive will-o'-the-wisp.

In the introduction to his paper McHargue seems to argue that Van Slyke's method may be applied directly to feeding stuffs without necessarily securing inaccurate results. Even if we should grant that the presence of carbohydrates per se did not vitiate the results, and all available evidence is contrary to such a conclusion, there would still remain other forms of nitrogen than proteins in the feeding stuffs which must necessarily appear in the various fractions and be wrongly calculated as amino acids. For example, Steenbock' reports the presence of stachydrin in alfalfa and this substance would be calculated as "histidine" in a Van Slyke analysis. I have elsewhere2 fully discussed this point and therefore have no hesitation in making the following statements: (1) Proteins can not be hydrolyzed with 20 per cent. hydrochloric acid at atmospheric pressure in the presence of a considerable quanity of carbohydrates without appreciably altering certain of the nitrogen frac

7 H. Steenbock, Sci. Proc. Soc. Biol. Chem., XXVII., 1916; J. Biol. Chem., Vol. 29 (1917).

tions of a Van Slyke analysis, and (2) a Van Slyke analysis applied to feeding stuffs, containing as they do non-protein nitrogenous compounds, gives no valid index as to the presence or absence of any individual aminoacid. Ross AIKEN GORTNER DIVISION OF AGRICULTURAL BIOCHEMISTRY, UNIVERSITY OF MINNESOTA

THE ACADEMY OF SCIENCE OF ST. LOUIS

AT a meeting held on May 20 Professor Francis E. Nipher stated that he had been making observations on local variations in the electrical potential of the earth, due to local thunderstorms. The large masses in the Cavendish apparatus are connected with a wire passing through a window in the second story of the physics building to the earth. The wire is in contact with wet grass in the yard below, and with metal rods which are pushed down into wet ground to a depth of about 15 inches. The lightning rod which grounds a high metal tower on the building, which was formerly used for wireless telegraphy, has been broken near the earth, and a gap of about two inches has been made in the rod. This rod can at any time be put in metallic contact with the large masses, by means of a knife switch. On several occasions during storms, sudden changes in the attraction of the large masses upon the suspended masses within the metallic shield have occurred, which it seems impossible to explain except as due to enormous changes in the potential of the large masses, due to local changes in the electrical potential of the earth. Previous results show that this would change the gravitational attraction between the N. M. GRIER, Recording Secretary

masses.

SCIENCE

A Weekly Journal devoted to the Advancement of Science, publishing the official notices and proceedings of the American Association for the Advancement of Science Published every Friday by

THE SCIENCE PRESS

LANCASTER, PA.

GARRISON, N. Y.

NEW YORK, N. Y. Entered in the post-office at Lancaster, Pa., as second class matter

SCIENCE

FRIDAY, AUGUST 9, 1918

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SOME ENERGY RELATIONS OF

PLANTS1

THE science of botany is about one hundred and fifty years old. Great changes have occurred during this time in the point of view from which botanists look at the plant.

The first scientific interest in plants was in merely naming them. In the latter part of the eighteenth century Linnæus extended the use of generic names which were already in use, added species names for greater convenience in handling his herbarium specimens, and thus established the binomial system, now in universal use in naming plants. Thus was laid the foundation of taxonomy as the earliest phase of the science of botany.

Linnæus clearly saw that the next step in the advance of botanical knowledge was to be classification. He himself made some crude attempts at arranging plants in classes. His system he well knew to be artificial. He clearly foresaw that more complete knowledge of the structure of plants, particularly of their buds, flowers and fruit, would ultimately lead to the classification of flowering plants in a natural system. His successors were busy with the attempt to learn enough of this structure of reproductive parts to enable them to put plants into a systematic classification according to their natural relationships.

This gave rise to morphology as the second great phase of the advance of botanical

1 Address as retiring president of the University of Washington Chapter, Sigma Xi, Seattle, June 4,

1918.

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