stables, which contain the discharges from typhoid or cholera patients, or the poisonous bacilli of scarlet fever, diphtheria, consumption, glanders, etc., are carted through our streets in open, leaky wagons, leaving a trail of filth and poison. Nothing can be more criminally careless and disgusting than the manner of carting dead animals through our streets on open carts; many of them, too, having died of the most contagious diseases, their poisonous secretions being deposited on our crowded thoroughfares.

In hundreds of cases of the contagious diseases, whose source is considered so mysterious, the contagion is inhaled with the street air. The poisonous material becomes desiccated and mixed with the sand and dust of the street and whirled about by the wind.

A smooth-surfaced street kept well swept, sprinkled before sweeping, and frequently well washed, reduces the chances of street contraction of contagious diseases to a minimum. Every garbage cart should be built and kept constantly under the surveillance of our health department. All garbage should be destroyed by fire. Every city should have its garbage crematory. The dumping or depositing of poisonous garbage and refuse material within the city limits is a satire upon a health department. Every dead animal should be removed in a water-tight cart closely covered. The present revolting and dangerous manner of carting dead horses through our streets on open carts is a reproach to our health department. Some of the diseases of which these animals die are most virulent and fatal to human beings, their contagium possessing a particular enmity to man.

Another source of street contagion is our street cars and public carriages; hundreds of people with contagious diseases ride in these public conveyances. Children with diphtheria, or while the scarlet fever desquamation is in process, scatter the poisonous germs in profusion about the cars and carriages, consumptives deposit their bacilli-loaded sputa, and syphilitic patients leave the germs of their loathsome disease. It should be the duty of the health department of a city to reduce this source of contagion to its minimum. The usual washing of cars with cold water is extremely inefficient. Every car and carriage should be carefully cleaned and fumigated at least once a week.

We have as yet but one known material with which to construct an ideal street, a street that is capable of being kept in a sanitary condition, viz., bitumen.

Macadam is the best country road, but cannot be kept washed and made entirely aseptic for a city. Yet a macadam street, by being kept in good condition and well moistened, can be made a comparatively healthy thoroughfare, and on very steep grades is the only material that makes a street that can be used. Wood and brick are too porous for street material; they readily absorb the numberless poisonous street filths, and pollute the atmosphere with noxious vapors and life-destroying germs. It is possible to keep a stone street clean, by filling in between the blocks with cement or asphalt, which leaves no absorbing surface. But even cleanliness, though next to godliness, does not constitute a perfect sanitary street. There are other methods of destroying health and life than by poison. The noise and jar and rattle of carriages and heavy teams on stone streets, are very fatiguing to the nervous cells and destroyers of vitality. The excitement and turmoil and rush. of a great city are enormous taxes on our nervous systems, but when

we have in addition the day and night stone-street rattle and jar, the nervous system must sooner or later yield to the inevitable. With the unrest, the strain, the fret, fret, fret of stone jars and shocks, there is no rest, no peace, no undisturbed repose, and where rest and peace are not health cannot dwell, cannot be maintained. It should be the duty of our health department to prevent as far as possible the noises, i. e., air shocks and earth shocks. Nature has declared that rest and repose are essential restoratives, and that no brain can do its best work, can work to its full capacity, that has not had a few hours' rest, a few hours' freedom from air and earth shocks in every twenty-four.

Discussion of Paper Read by Dr. W. F. McNutt.

DR. WINSLOW ANDERSON: The subject of street sanitation I believe to be a very important one for the consideration of this convention. It is a fact, and I am sorry to acknowledge it, that San Francisco has almost the dirtiest streets of any city of its size in the world. The pavement is bad, as the doctor has pointed out in his excellent paper, but there is no excuse, there can be none, for keeping our streets in such a deplorably dirty condition. Every day when the winds are blowing the dust and dirt and microbes are inhaled by the multitudes on our streets. We know that disease may be communicated in this way. We know that drinking water and milk exposed to such dust become contaminated-they become disease-laden. Fresh meat, when exposed to atmosphere laden with germs, also absorbs pathogenic bacilli, and it does seem that something should be done, some attempt should be made to endeavor to keep our streets clean. I do believe that street sanitation in the manner indicated in this paper is a very important subject, and one worthy our attention.

DR. M. REGENSBURGER: Street sanitation in San Francisco could be better in many ways, it is very true. We have laws here which are never carried out. The doctor remarked in his paper that there were certain things that were not creditable to the Board of Health. I beg to differ with the doctor on that subject, for the reason that the laws have been passed by the Board of Health, but our Board of Health here is handicapped by its laws not being carried out. We simply make the laws, and the Board of Supervisors is supposed to carry them out. We have laws regarding garbage, and the removal of garbage, and that no garbage shall be removed from any house, except in air-tight wagons, so that none can escape, but as you pass the wagons it falls in your face. So the fault does not lie with the health authorities, but with the Board of Supervisors. Regarding the streets: The keeping of our streets in good condition is very simple if properly carried on, and the present system could be remedied very rapidly. I would like to remark right here, that I think Dr. Anderson is wrong when he says that the streets here are in a filthier condition than anywhere else in the world. The doctor has traveled, and I have traveled, and you take the large cities of the United States-take New York City or Chicago, and you will find the streets there in a great deal filthier condition than they are here. It is true everything cannot be done in one day. This city has, within the last five or six years, improved her streets by bituminous pavement, which is being laid all over the city as rapidly as it can, and in a few years San Francisco will be one of the cleanest

cities of the world. The question of cleaning the streets is a very simple one; that is, each individual property owner should be compelled by a very strict law to keep his part of the street clean. By this method the streets of San Francisco would be in excellent condition, and it would cost the city nothing. Simply pass a law compelling the property owners to clean the streets before their property; clean the sidewalks. We have a law preventing the throwing of garbage on the street, but it is a law that never has been carried out. Garbage is thrown all over the streets here, due to the negligence of the police department. The Board of Supervisors should enforce these laws. If our city were in as bad a condition as has been pointed out here, would not our mortality reports show the condition? San Francisco is, to-day, if not the healthiest, one of the healthiest cities in the world. The contagious diseases here are very few. I do not think that within the last year we have had more than twenty-five or thirty genuine cases of diphtheria. The same can be said of scarlet fever and typhoid fever. I do not believe in giving San Francisco a black eye-coming here and reading a paper on general sanitation, and then damning San Francisco. San Francisco is a healthy city, and one of the healthiest cities in the world, and it is a young city. If we had the proper authorities to carry out the laws, there is no doubt that there would not be a cleaner city in the world.

DR. W. F. MCNUTT: I would simply say that I am very glad to hear from Dr. Regensburger that we have good sanitary laws. I had not read the laws, but I have seen the streets, and while there may be laws against carting dead horses and dead animals over the streets, trailing their venomous secretions along in the track of the cart, nevertheless it is done, and I am very glad to know that the fault must be with the Supervisors, as the doctor says that there is a law against carting garbage in that way. I think it would not be doing, perhaps, too much to interview the Supervisors a little on this subject, and call their attention to it. Perhaps if the Board of Health were to follow them up a little we could get rid of a good deal of this. I have never been on the Board of Health; I hope I never will be; but nevertheless I am very glad to know that the trouble comes with the Supervisors. We will go after the Board of Supervisors.

EVENING SESSION.

DRINKING WATER, AND ITS EXAMINATION, CHEMICALLY CONSIDERED.

BY PROF. A. AUCHIE CUNNINGHAM, F.C.S

Mr. Chairman and Gentlemen: Drinking water is a compound. No one can tamper with it with impunity. The quantity of water which enters our system daily varies from three and one half to five pints, all of which, however, is not necessarily drunk, as about one third is taken in the form of solid food. Thus, we see, an average person swallows every week about three and one half gallons of water; therefore, we can readily understand, should there be but a small trace of injurious matter present, either organic or inorganic, it would soon assert its painful effect.

Pure water is never met with in nature; the most transparent ice and the clearest rain water contain foreign substances. In fact, pure water is a curiosity in the chemical laboratory. Presenius found, on distilling 42.41 grammes of water in a glass flask with great care, that it subsequently left on evaporation 0.0018 grammes of solid residue. Mr. Crooks, in determining the atomic weight of thallium, found it necessary to distill the water in special apparatus in vacuo. We, however, find, when water is distilled in the usual way in properly constructed stills and condensers, made of the right material, that it answers all the ordinary requirements of the chemist. I am sorry to state that sometimes we find in chemical laboratories the distilled water being polluted by the vapors so commonly found in the atmosphere, owing to the absence of a wash bottle containing purifying chemicals, through which all air coming in contact with the water should pass. I have also seen, where an important analysis of water was being made, a wash bottle in use, the contents of which had been blown upon by the operator so long as any water could be expelled, and this same water, which could not avoid being contaminated by the breath, would be used in making the analysis for organic matter; no attempt being made to boil the water before use.

It is, however, not with pure water that this paper deals, but with drinking water. This, we find, always contains matters in solution, both gaseous and solid. Where free from the former the taste would be insipid, and should the latter be absent or only present in very small amount and not composed of the proper constituents, the number of cases of rickets would increase rapidly, as is the case in many towns where the water supply contains only a trace of lime. The quantity and nature of these matters held in solution are therefore important questions to be taken into consideration when we examine the water chemically. The quantity must therefore be determined and its nature in relation to health thoughtfully considered.

The first thing necessary in making an examination of water, so that the results may be of scientific value, is to obtain a fair sample. The bottles in which the samples are to be taken require to be not only chemically clean but thoroughly sterilized. In preparing sample bottles they should be cleaned with good water and then about two ounces of C. P. hydrochloric acid should be poured in and every part of the inside of the bottle brought in contact with it. This should then be removed and the bottle filled at least four times with good water and finally twice rinsed with distilled water. It should then be rendered sterile with steam, and a clean cork placed in the neck. During the past four months I have refused to examine five samples of water out of sixty-five sent, because after all precautions regarding cleanliness of bottles had been taken, dirty corks were inserted.

In sampling water from wells the bottle should be plunged about six inches below the surface and the cork then removed, thus avoiding all chances of surface contamination. When full it should be withdrawn, an ounce of water poured out, and corked. When taking samples from streams, all inlets and outlets should be avoided. When reservoirs or lakes are to be examined, samples should be drawn at various depths by a special apparatus, also at different parts, as well as from the bottom and surface, and one or two from any part which shows likelihood of contamination from surface drainage, which I am sorry to state I have found to be not uncommon, in one or two instances, where I took samples from reservoirs supplying cities in this State from the proximity of farm yards, hog pens, etc. Where possible, the chemist or bacteriologist should take his own samples, and thus avoid the question of an unfair sample. Should this be impossible, then the samples should be sealed and kept in a cool place until they can be shipped to the expert, which should be done without any delay. In the case of bacteriological examinations, time between sampling and inoculation of tubes is an important factor, and where this, owing to travel, would exceed the limit laid down by authorities, the expert can take his tubes along and place his drops of water in them on the spot.

For making water analyses the chemist should have a special room, free from the fumes found in the laboratory. This point is not always attended to, and I know of important analyses of city supplies being made alongside of assay furnaces in full blast, to say nothing of the ammonia bottles lying on the shelves and the dust floating about in the atmosphere.

The modus operandi of water analysis is well known. I will therefore treat with the results of a chemical report, and give the figures which have stood the test in epidemics where water contamination was at the fountain head, and where, when the polluted springs, wells, or reservoirs were cut off from the supply, the increase of the maladies was stopped inside of a few days, or in hours. When such outbreak occurs time is an important factor, and this is one advantage which chemical analysis has at present over the new and slower process of bacteriological examination.

A sanitary analysis of water gives these results: (1) Total solid residue, or the weight of matter left on evaporating a given quantity of water to dryness over a water bath and subsequently heated in an air bath. This residue varies with different water supplies, and all authorities agree that when this residue is under 5 grains to the gallon,