POPULAR MISCELLANY. 



859 



principles arc cited, the grouping of which 

 makes it evident to the author that symp- 

 toms of alcoholic poisoning can not be 

 trusted as evidence of the immediate use 

 of alcohol ; and that the excessive use of 

 alcohol leaves a permanent defect or im- 

 press on the brain, which will go down into 

 the future with great certainty. It may be 

 concealed for a lifetime in the child of a 

 drinking parent, but may come to the sur- 

 face at any momeut, from the application of 

 its special exciting cause ; or it may appear 

 in some other form of defect, which can be 

 traced back to the injury from the toxic 

 action of alcohol. 



Potable Water. — The unsatisfactory 

 character of all purely chemical examina- 

 tions to determine the wholesome potabil" 

 ity of water has long been tacitly admitted. 

 It has more recently been demonstrated that 

 such examinations do not go to the root of 

 the matter, for the quality of water is de- 

 pendent on the presence or absence of cer- 

 tain bacterial growths. Frankland's com- 

 bustion process, Wanklyn's ammonia pro- 

 cess, and Schiitzenberger's permanganate 

 of potash method, were all attempts to esti- 

 mate the organic matter, and, to some ex- 

 tent, its qualities ; but they, and all chemi- 

 cal processes, deal with dead matter only, 

 or, rather, fail to draw any distinction be- 

 tween the living and the dead ; and, judged 

 by these standards, the water in which vege- 

 tables have been boiled, or a cup of meat- 

 broth, or of coffee, would rank far worse 

 than water containing a small quantity of 

 enteric or choleraic stools, or even than the 

 anthrax-bearing waste from a mohair-fac- 

 tory. Bacterioscopic examination of water, 

 the object of which is to determine the bac- 

 terial life, or the disease-germs and their 

 activity, has been employed for some years 

 in Germany, and is making headway in Eng- 

 land. By this method we are enabled to 

 ascertain the number of living bacteria in a 

 cubic centimetre of water. Koch's results 

 showed the relation between this number 

 and the purity of waters, as well as the effect 

 of filtration, when he was able to announce 

 that the numbers were, for Berlin Bewage, 

 38,000,000 ; for the waters of the Spree, 

 118,000 ; for the effluent from sewage-farms, 

 18,000 ; from the Rummelsberger See, 32,- 



000 ; from the Stralau water-works, before 

 filtration, 125,000, and after filtration, 120. 

 In the best well-waters it is from 30 to 60, 

 and in boiled distilled water from 4 to 6. 

 From this it appears that any number under 

 100 indicates an irreproachable water, and 

 under 200 a potable one ; while polluted 

 rivers count their thousands and sewage its 

 millions. Still, this method fails to distin- 

 guish between innocent and pathogenic or- 

 ganisms. Some of them can be identified 

 by their mode of growth in tubes of nutri- 

 ent gelatin, by their behavior with coloring 

 reagents, and by other methods, even when 

 in themselves morphologically alike and in- 

 distinguishable under the microscope. Dr. 

 Dupre suggests an easier and speedier plan, 

 dependent on the fact that some microbes 

 can and others can not survive exposure to 

 certain degrees of heat, and that while dead 

 matter rapidly absorbs oxygen from per- 

 manganate of potash, it does so to a very 

 slight extent, if at all, from the water it- 

 self, at least within a limited space of time. 

 He is directing his attention to the points 

 that the amount of oxygen taken from the 

 water in its natural condition may be con- 

 trasted with that taken from the perman- 

 ganate ; that it may be contrasted with that 

 taken up after any living organisms in the 

 water have been killed by the application 

 of heat ; that a degree of heat may be ap- 

 plied sufficient to kill developed organisms 

 or certain germs and spores, but insufficient 

 to kill other kinds of germs and spores, and 

 if this degree of heat be known for the 

 several kinds of germs and spores, a judg- 

 ment may be formed as to the nature of 

 the germs and spores present ; and that 

 some substances, sterile in themselves, but 

 capable of nourishing any living organisms 

 contained in the water, may be added, and 

 the increase in the amount of oxygen ab- 

 sorbed may be noted. Among the practi- 

 cal results to which Dr. Dupre has come, 

 are : A water which does not diminish in its 

 degree of aeration, or, in other words, which 

 does not consume any oxygen from the dis- 

 solved air, may or may not contain organic 

 matter, but presumably docs not contain 

 growing organisms. Such organic matter, 

 therefore, as on analysis it may be found 

 to contain, need not be considered as " dan- 

 gerous organic impurity " ; a water which, 



