any relief from their nervousness in Colorado. In fact, this class of cases are likely to become more nervous here unless a very quiet life is lead. Of course, there are exceptions to this broad

statement.

Mental Depression in tuberculous subjects is more common here than what is found at sea level. There are several reasons for this state from causes other than climatal. Patients here are often separated by hundreds or thousands of miles from relatives and friends, and they feel their isolation and loneliness keenly. They frequently come here with insufficient means for their support, and are compelled to seek some employment immediately on their arrival, or before they are able to do any kind of work. I have seen an undue proportion of cases of severe mental depression and melancholia among these two classes of cases. Melancholia is exceedingly rare in the better favored classes of tuberculous subjects.

The question may be asked: Is tuberculosis more likely to attack the central nervous system in Colorado than is found to be the case at sea level? In the adult, I think we may safely answer in the affirmative; in children, if we take into account the larger proportion of tuberculous parents in Colorado, it seems to me that we are justified in answering in the negative. The reason for the central nervous system in the tuberculous adult suffering more frequently from tuberculosis than what is found at sea level is not far to seek. Of the great number of tuberculous patients that come to Colorado for their health only a small per cent are permanently cured. Not an inconsiderable number die after a few months' or a few years' residence here, while the vast majority that do well live many years and lead comparatively useful and active lives. These always remain tuberculous, with a lessened power of endurance and resistance. They often do as much work as healthy persons, and often more, and expose themselves until at last their vitality is permanently far below normal, when the tuberculous processes begin to attack the various organs of the body, until finally the bacilli find entrance to the central nervous system, especially to the membranes of the brain. In a few words, tuberculous subjects live longer in Colorado than at sea level, more tissues are invaded by the bacilli and the membranes of the brain form no exception to the general process of invasion.

How are such functional diseases of the nervous system as hysteria, neurasthenia (commonly known by the laity as nervous prostration), chorea, epilepsy, migraine, nervousness or nervous

excitability, insomnia and neuralgia influenced by the climate of Colorado?

Hysterical subjects do better at sea level than in Colorado, unless the hysterical manifestations are due to depressed states of health that are relieved by a residence in Colorado.

Neurasthenia.-The same may be said of neurasthenic subjects, except that some of the causes of neurasthenia are more commonly removed by a residence in Colorado than are those of hysteria. Neurasthenic persons should lead quieter lives in Colorado than at sea level. It is here that the Weir Mitchell "Rest Cure" shows off to excellent advantage.

Sufferers from sick headaches, or migraine, usually do better at sea level than in Colorado, although the headaches are often relieved for a time on the patient's first coming to Colorado, but are made worse by a prolonged residence here. After a short stay here sufferers from sick headache are often free for months. on returning to low altitudes. The ideal life for those afflicted from migraine is a frequent change of climate from Colorado to sea level, living at least two-thirds of the time at low altitudes.

Choreic patients should not be sent by choice to Colorado for treatment, because all such functional nervous diseases are more or less unfavorably influenced by the climate here, especially when the altitude exceeds 4,000 to 5,000 feet. However, if by force of circumstances choreac children are compelled to come to Colorado, they can be cured in about as short a time here as they can at sea level, provided the precaution is taken to keep the patients in bed until all violent movements have subsided.

Epileptic patients seem to be unfavorably influenced by the climate here, but not nearly to the extent as is popularly believed. As a rule, the higher the altitude the more violent and frequent the attacks.

The nervous and the impressionable from childhood are less comfortable in Colorado than at low altitudes, but they can reside here with comparative comfort if they live quiet lives and do not enter into business or social engagements that are too exacting. On the other hand, those who have become nervous and rundown East by worry, over-work (especially the mentally exhausted), too great social cares, and by bearing burdens too great for their strength, come to Colorado and live quietly, without allowing themselves to become mentally or physically exhausted, do well here and apparently regain their health more

rapidly than at sea level. One apparent reason for this result is the amount of sound and refreshing sleep obtained here for this class without the use of hypnotics.

Insanity is less frequent here than in the Eastern states, in proportion to the population. It runs about the same course here as it does at sea level, with the exception of the excitable and wildly maniacal, whose irritability is apparently increased by high altitude and a dry atmosphere.

Organic Disease of the Nervous System.—I have been unable to observe any marked difference in the frequency, course and results of this class of nervous diseases here from what I found to hold in Philadelphia, in which city I practiced for nearly ten years before being forced to seek Colorado's climate.

CLINICAL VALUE OF THE EHRLICH DIAZO TEST.* By W. T. LITTLE, M.D.,

Canon City, Colorado.

In 1882, Ehrlich, believing that in the urine of certain diseases aromatic or chromogenic bodies were excreted which would become diazotized under proper chemical treatment, experimented upon the urines of a large number of infectious and non-infectious diseases, and obtained a specific diazo-reaction, especially in the urines of typhoid fever and tuberculosis. The chemistry of the reaction will not here be considered. The reagent is made as follows, and consists of two solutions, which should be kept in separate bottles and protected from the light and heat. Solution No. I consists of sulphanilic acid, I part; hydrochloric acid, 50 parts; distilled water ad 1,000 parts.

parts.

No. 2.-Sodium nitrate, 0.5 part; distilled water, ad 100

The proportion of sodium nitrite in No. 2 has been varied by a number of observers, and this has in some instances-Munson and Oertel-been the cause of their failure to get satisfactory results. Several methods, too, have been suggested. Ehrlich advised the addition of 5 parts absolute alcohol to I part urine previous to the addition of the sulphanilic acid mixture. This

* Read before the Southern Colorado Medical Association, May 15, 1901.

seems to be unnecessary, however, and the following method has been generally adopted and is the one I use:

To 40 parts of No. I add 1 part of No. 2 in a small test tube. Then add an equal quantity of urine, which should not be over 24 hours old. Shake; then add slowly from a pipette about I c. c. of aqua ammonia. At the junction of the urine mixture and the ammonia a ring is formed, which, if the diazo reaction is present will be of a deep red color, varying from osin to a deep garnet. A reddish brown or yellow ring which is frequently present is not to be mistaken for the true diazo color. If the mixture is now vigorously shaken the foam will be of a pronounced pink color which is distinctive of the test, and without which we should consider the test negative.

In measuring the 40 parts of No. 1 and 1 part of No. 2 I employ a 1 c. c. pipette which holds to the mark approximately 40 drops. To fill this takes less time than to use a dropper and is sufficiently accurate.

Having briefly outlined the test and the method for its use, we will consider its clinical value. At one time it was considered pathognomonic of typhoid fever, but subsequent researches have shown that it is frequently present in tuberculosis, pneumonia, malaria, scarlatina, cancer, sepsis and a number of other diseases; but in spite of this its value as a diagnostic agent in typhoid fever is but little invalidated. True, we cannot rely upon it alone, but we should never depend upon laboratory methods to the exclusion of clinical data. The Widal test is more exact; but only the comparative few who have access to the bacteriological laboratories of our cities can use it. The Ehrlich diazo test is simple and inexpensive, easily made by any physician, and its reagent bottles should be as familiar as the nitric acid bottle in the country doctor's office. Were this so, error and delay in the recognition of that protean disease, typhoid fever, would be far less frequent. Typhoid-malaria and "mountain fever" would be things of the

past.

Given the reaction, the disease which would be most apt to be mistaken for typhoid fever is acute miliary tuberculosis. Simon says that "this should not be difficult, as the reaction is obtained not later than the twenty-second day of the disease, and is usually present as early as the fifth or sixth day in typhoid fever; and that it generally does not appear earlier than the beginning of the third week, and then persists almost to the end in acute tuberculosis." In one case of mine the reaction was found

on the third day; another on the fifth day. These were ranchmen who came to my office. I found fever and the diazo reaction, and was thereby enabled to make a positive diagnosis at the first visit. In neither case was there anything else distinctive of typhoid.

On the other hand, the reaction may be delayed, as in the case of a child aged 5 in which I was unable to get the reaction before the thirtieth day, and then it lasted until the forty-fifth day, when the temperature reached normal.

Of 932 cases of typhoid fever examined by a number of observers 91 per cent. gave the reaction.

Out of a total of 82 cases of tuberculosis examined by Arneill (2) the diazo reaction was present in 42.

The reappearance of the reaction in typhoid denotes a relapse, as it does not seem to be produced or affected by the occurrence of complications as phlebitis, hemorrhage, pneumonia, etc. The first time I used the test was in that of an unusually interesting and puzzling case, and it impressed me most favorably as to its value as a diagnostic agent. The case was that of a girl aet. 12, who had been ailing for about two weeks. Six days before I saw her it was noticed that both eyelids were puffy, and two days later the entire face was swollen, the temporals being decidedly so. The swelling was symmetrical and non-inflammatory, and did not pit on pressure. Her mother thought she had had a little fever for two days. There was slight nausea. For twenty-four hours there had been decided stiffness in the shoulders and elbows. The afternoon temperature was 102°, pulse 116. The following day I did not see her, but her mother thought there was no fever. There was stiffness in the knees. Forty-eight hours after my first visit I saw her and found the afternoon temperature 100°, with moderate swelling and tenderness of the left ankle, and slight soreness of the other joints. She had been sweating some. I now promptly diagnosed acute rheumatism and placed her on the appropriate remedies. The fourth day the feet were swollen and there was pain in the right thigh. Fifth day the temperature was 100° with considerable sweating and pain in the legs when they were moved. The temperature then fell to normal. On the sixth and seventh days her condition was about the same with no fever. I now applied the Ehrlich diazo test and got a strong color reaction. The following day the clinical picture changed and it became that of a typical mild typhoid, the temperature reaching normal twenty-two days after her face began swelling.