ation. An estimation of the number present may be conducted as follows: The water should be received in a sterile bottle or flask. The bottles should be of hard, clear white glass, with glass stoppers. They should have been carefully washed and rinsed and sterilized with dry heat, for one hour at 160 degrees C. For transportation they may be wrapped in sterilized cloth or paper or the necks may be covered with tin foil. Every precaution must be taken to guard against subsequent infection

The minimum quantity required for a bacteriological analysis is two ounces. In special cases larger quantities may be required. The analysis of the sample should be made as soon as possible, after collection, since the number may increase rapidly. Especially is this the case in water brought from a cool source to ordinary temperatures.

Six hours may be regarded as the maximum limit before plating, and if necessary, that a longer interval elapse, the specimens should be packed in ice until used. Care must also be taken to secure a sample which is truly representative of the water to be tested. This is especially important in water polluted by sewage. It follows from this that it may often be necessary to examine a number of samples collected at different times and places and under different conditions.

In order that acurate and uniform results be obtained, it is well that all media used in these experiments be made as directed by the methods recommended by the American Public Health Association.

The water is measured in sterilized pipettes, and gelatine tubes are inoculated with a given amount of water, for examination. Tube one receives one cubic centimeter of water. Tube two one-half cubic centi meter. Tube three, one-tenth cubic centimeter. This being thoroughly mixed with the gelatine which had been previously melted, it is poured into sterile Petri dishes and set aside at ordinary room temperature until the colonies develop.

If only a small number develop, they may be easily counted, either by the naked eye or by placing under the low power objective of the microscope.

If a large number appear, a counting apparatus may be used. A black paper ruled into squares, placed under the dish, will suffice. A certain number of squares may be counted and an average made and on this basis the approximate number in the dish ascertained.

Knowing the amount of water with which it was inoculated, the number of colonies represent the number of germs which were present in that amount of water-since each colony grew originally from a single

germ.

This, however, represents only the minimum, for a bacillus growing in pairs may form only one colony, or conditions may not be favorable. for development, since some may have been bacteria, growing only at body temperature.

The recognition and classification of the different varieties of bacteria found in water, is interesting to the laboratory worker, but it is not until we study the disease producing germs that the process has a direct bearing on the sanitary condition.

The two chief types of disease producing organisms found in water are the Bacillus Typhosus and the Vibrio of Asiatic cholera. In this latitude and climate it is with Bacillus Typhosus we are most concerned.

Careful and experienced bacteriologists do not now claim to be able to isolate the typhoid bacillus from natural waters. The effort has failed even in water that is obviously polluted.

In sterilized water and in very highly polluted water or sewage, the typhoid bacillus does not flourish. In the former case it may be due to starvation and in the latter it is killed by the enormous competition of common bacteria. This brings about two characteristics, which it is important to remember that the typhoid germ in water is, as a rule, scanty and intermittent. It has of course, in a number of cases been detected but its detection is difficult. It is, to begin with, enormously diluted, a small amount of infectious material being introduced into large quantities of water.

A bacteriological examination of water suspected of having conveyed the disease is, from a variety of circumstances, conducted too late to detect the causal bacteria.

The period of incubation may be counted as fourteen days. Should a town water supply be infected by typhoid on January 1st, until January 14th, there may be no knowledge of the state of affairs. Two or three days are required for notification of cases, several more before bacteriological evidence is demanded. Hence arises the anomolous position of the bacteriologist who sets out to examine a water supply suspected of typhoid infection three weeks previously.

The solution of the problems will be found in the dictim, that, "A water in which sewage organisms have been detected in large numbers should be regarded with suspicion as the vehicle of typhoid even though no typhoid bacilli are discoverable."

There are several of these sewage bacteria or bacteria of indication as they are termed. In this group is found the bacillus coli communis bacillus entenditis sporogenes, the Proteus family, and certain streptococci, and staphylococci. In default of a method of detecting the typhoid bacillus, resort is had to methods of detecting these sewage bacteria, especially the bacillus coli communis. This being always associated with dangerous pollution, the detection of it in water indicates previous contamination.

This organism itself, under ordinary conditions, is not likely to be harmful, but it serves as an index of sewage or surface pollution.

In testing water to determine the presence of coli, we may resort to a variety of expedients. In the first place, we may proceed to count the colonies by placing a certain amount of the suspected water in melted gelatin or agar tubes, and after mixing thoroughly, pouring into Petri dishes.

When the colonies develop, they are studied under the miscroscope and any which may resemble the coli may be picked out with a sterile platinum wire and planted in fresh tubes of agar or gelatine.

Agar, or gelatine, which has been colored blue by litmus, is sometimes used. Coli being an acid producing organism, will, if present, turn this media red.

We may make stained preparations on cover glasses, also study the suspected colonies by making from them hanging drops from which to study the motility of the organism.

There are still some more striking cultural characteristics which we may utilize. The coli has the power of splitting up glucose and lactose into simpler constituents, carbon dioxide and hydrogen being formed. We accordingly make use of this property by making up a media containing two per cent of glucose or lactose.

We may grow some of the germs in a beef tea containing one of these, and instead of an ordinary test tube use a fermentation tube. In this tube may be placed two or three centimeters of the suspected water, well mixed with beef tea, taking care that no air be left in the upright arm of the tube. This may be left at room temperature or be placed in the incubator. The most favorable temperature for the coli is said to be about 41 degrees Centigrade. Should coli be present in the water it will soon begin to work on the sugar and in a short time the upper part of the upright arm will be filled with gas.

A still simpler method is to add some of the water to a melted gelatin or agar tube, which contains glucose or lactose. The tube contents are then allowed to solidify, but if coli is present in twelve hours or more, the contents of the tube will be torn apart by the gas formation.

Since the coli belongs to the acid forming bacteria, if grown in a tube of sterile milk, the milk will rapidly sour and coagulate. This too, may be used as a test.

It will require several days of work and observation to establish its identity beyond doubt, but if we find a short thick bacillus which may be slowly motile, sometimes non-motile, which does not liquify gelatine, does not stain by Grams' method, will curdle milk, produce gas in sugar media, and usually produces indol in peptone water, we may be fairly sure of its presence..

If we find this germ in the water, we know that the water is polluted.

In conclusion, it may be stated that drinking water is considered safe:

First. If there is an absence of disease germs. But we must remember that true disease germs can seldom be detected.

Second. If there is absence of the bacteria capable of fermenting glucose or lactose.

Third. If it contains comparatively few bacteria.

Especially when these conditions are found to exist as the result of several examinations or periodic examinations, the water may be considered safe.

tion.

REFERENCES.

George Newman, Bacteriology and Public Health.

Standard Methods of Water Analysis, American Public Health Associa

Report of committee appointed by the Royal Institute of Public Health, to consider the Standardization of Methods for Bacteriological examinations of water.

Medical Department Notes

Several very fine microscopes have been added to the equipment of the Biological Department.

Dr. Giffin will deliver a special course of lectures this semester on "Life Insurance Examinations."

The University Hospital staff has been more closely organized and now holds regular staff meetings.

Dr. Johnston spent the holiday vacation in Chicago collecting pathological material for his department.

Dr. Chase has been unable to meet his classes for several weeks, owing to a severe attack of myocarditis.

The death of Dr. Geo. Lindenkohl, of the class of 1900, is reported as occurring at Washington, D. C., September last.

Our Obstetrical Department this year is unusually fortunate in obtaining clinics. So far they have been ample for our needs.

Dr. Bair attended the general meeting of the Sigma Xi during vacation at New Orleans, as a delegate from the University chapter.

Dr. Miles delivered an address before the University Scientific Society on the subject, "Preventive Medicine," February 19th, '06.

Alumni are requested especially to contribute to the "Bulletin.” Original articles, case reports, or editorials, are always acceptable.

The annual alumni banquet was held at the Brown Palace hotel, Denver, January 27th. It was largely attended and eminently successful.

Dr. Arthur E. Gill, Ass't. Surgeon of C. F. & I. Hospital at Pueblo, was a recent visitor at his Alma Mater, the Colorado School of Medicine.

The course in operative surgery, on dogs, is given this semester by Dr. Miles. This is one of the most interesting courses of the department.

The caps and gowns are again in evidence. All members of the faculties and members of the graduating classes are to appear at commencement this year in caps and gowns.

At the January meeting of the Boulder County Medical Society, Dr. Jacob Campbell was elected President; Dr. F. R. Spencer, Secretary; and Dean Giffin, Delegate to the State Society.

Dr. Duane is giving this semester, a course in physics to Juniors, that has special reference to medicine. It will, no doubt, be a very valuable addition to our medical curriculum.

Dr. A. K. Carmichael, a prominent physician of Trinidad, Colo., was a recent visitor at the University. His son may enter the Medical Department as a student in the near future.

The large microtome, for cutting whole sections of the brain, etc., has arrived from Germany and is installed. It is perhaps the largest apparatus of its kind to be found in the West.

The practical systematic course in post mortem examinations, which our classes are getting this year, is greatly appreciated. So far there has been abundance of material and all of it full of interest.

Dr. R. W. Corwin began his course in abdominal surgery with the opening of the second semester. The wide renown of Dr. Corwin in this particular line of work, predetermines its interest and value.

The Senior students have been personally, very unselfish, in contributing their share to the surgical clinics. Mr. Kenagy was recently operated on for appendicitis, and Mr. Kellogg for disease of the antrum of Highmore.

Dr. Phil. Davis has been promoted to the position of House Surgeon at the New York Lying in Hospital, the largest Maternity Hospital in the world. Four hundred and thirty-five cases were delivered there in the month of January, '05.

In this issue we publish a complete list of the Alumni of the Medical School. Alumni are requested to send to the Secretary, Dr. M. E. Miles, Boulder, Colo., the proper address, if it is not so given in the list, and also any change of address.