virulence possessed by the tubercle bacilli. Some of this tubercle-infected sewage was poured over garden soil in which radishes were growing, and after the bacilli had spent eighty-eight days in these surroundings, during which time they had experienced frost, snow, rain, and sunshine, they still retained their virulence. Of special interest are the investigations Dr. Musehold made to ascertain if tubercle bacilli could be detected on the fields attached to a hospital for consumption and irrigated with the sewage from the same. Not only were tubercle bacilli found, but they were also, as was to be expected from the laboratory experiments cited above, discovered in a highly virulent condition.

That disease germs may be distributed with the vegetables grown on municipal sewage farms is not a mere whim or fancy of the faddist, but is a very real danger, and must be regarded as a menace to the health of all who consume such articles as lettuces, radishes, celery, and other vegetables which are not first cooked before being placed on the table.

This forcibly suggests the desirability of all expectorations from consumptive patients being thoroughly disinfected, or, in other words, deprived of their virulence before being admitted to sewage.

The importance of such precautions being taken

is borne out by the examinations of the clear effluent derived from the treatment of the sewage of a consumptive hospital which revealed the presence of virulent tubercle bacil!i, whilst they were also discovered in the bottom of a ditch conducting the effluent away.

Such facts as these deserve the earnest attention of all public authorities, and it is to be hoped that the overwhelming evidence which is now available regarding the distribution and Spartan character of the tubercle bacillus will lead to serious efforts being made to bestow upon it that measure of consideration which in the case of recognised zymotic diseases leads to the enactment of rules and regulations for the restriction at least of the fateful activities of these malignant foes of mankind.

Before leaving the subject of bacteria in relation to water, it will be interesting to glance at what is known regarding the attitude taken up by these minute forms of life towards that large and ever-` increasing class of waters vaguely grouped together under the synonym of mineral waters. The fortunes made in manufacturing artificially aërated waters and the mine of wealth contained in a new mineral spring are sufficient evidence of the popularity enjoyed by this description of beverage. The beer and spirit statistics of the

country and their contributions to the national revenue do not, however, permit us to indulge in the belief that this large consumption of harmless drinks is due to their displacing the use of intoxicants—the increasing sale of non-alcoholic beverages cannot in fact be taken as an index of the growing sobriety of a nation; far more must the greater demand be attributed to the improvements in manufacture which have cheapened production and placed what was formerly an article of luxury almost prohibitive in price, and hence reserved for the few, within comparatively easy reach of the many. Perhaps also an increased sale may be assisted by a prevailing impression that by substituting carbonated for ordinary potable water, the risk of contracting zymotic disease is, if not altogether removed, at any rate very materially diminished.

It will be therefore instructive to see how far this assumption is justified by actual facts.

The first fact to be recognised is that the number of bacteria present may and does fluctuate between such wide limits as is represented by as few as three, and as many as 100,000 being found in about twenty drops of artificially aërated waters. Seltzer water, manufactured from well water, was found by Sohnke to contain numbers varying from 200 to 6,000, whilst when only distilled water

was used, ie. water previously deprived of all bacterial life, only from ten to thirty microbes were present. But an important and far too little recognised factor in the manufacture of aërated waters is the contamination which so frequently takes place subsequent to the initial purification of the water by sterilisation. In some instances this contamination is due to the storing of water before use in reservoirs, where an excellent opportunity is offered for microbial multiplication.

Merkel found water which originally only boasted of from four to five bacteria per cubic centimetre, subsequently, when ready for distribution as seltzer water, contained considerably over 3,000. In this case storage had been resorted to. Again, insufficient importance is attached to the efficient cleansing of the syphons on their return to the factory. The experiments made by Slater in this country and Abba in Italy have conclusively shown that the gaseous aëration of water exerts an inhibitory action on the growth of at least some varieties of water bacteria, for both these investigators found that in proportion as the amount of gas present was diminished by being allowed to escape, so was the multiplication of the bacteria present promoted and their numbers increased. Unsavoury as may be the idea of swallowing down myriads of even harmless

microbes, yet the real significance of the whole question from a hygienic point of view lies in the evidence as to the fate of disease germs in aërated waters.

On this important matter there fortunately exists some precise and conclusive information in regard to the bacteria associated with two essentially water-borne diseases, i.e. typhoid fever and cholera. The investigations made to test the vitality of the anthrax bacillus are of significance as again emphasising the superior degree of vitality possessed by the spore over the bacillar form of this micro-organism, but the chances of this disease being disseminated by water are usually regarded as too remote to excite much interest in the fate of the b. anthracis in seltzer water. It may, however, be mentioned that whereas the bacilli succumbed after being in the seltzer water from fifteen minutes to an hour, the spores were still living after one hundred and fifty-four days. Investigations on the vitality of cholera bacilli in aërated waters have been made by Hochstetter in Germany, by Slater in England, and by Abba in Italy, and these various authorities all agree that the lease of life of these micro-organisms is a very short one in ordinary unsterilised carbonated waters, and that they are in fact destroyed in from half an hour