92 



CHEMISTRY. 



Use of Carbolic Acid. The value of carbolic 

 acid as a disinfectant has been severely at- 

 tacked of late. The English Mechanic prints 

 an article declaring carbolic acid far inferior to 

 common chloride of lime. The effect of the 

 former is short, and it does not destroy the 

 vitality of infectious germs. The writer com- 

 pletely disinfects apartments by stopping up all 

 the openings, and placing in different parts of 

 the room several plates containing common 

 salt and a little vitriol. A chlorine vapor is 

 evolved, and the seeds of infection are de- 

 stroyed. This opinion of the inferiority of car- 

 bolic acid is not shared by most authorities, 

 though all agree that its odor is highly offen- 

 sive. To overcome this objection, Prof. 

 Church prepares the acid for use in the follow- 

 ing way : He pours one pound of the best com- 

 mercial article of carbolic acid into two gallons 

 of distilled water (cold), not permitting the 

 whole of the acid, however, to enter into solu- 

 tion. The watery solution is siphoned off and 

 filtered, and then placed in a tall cylinder, 

 and powdered common salt added to it, till the 

 salt will no longer dissolve. After awhile, the 

 most of the carbolic acid will be found floating 

 on the top of the water, and may be skimmed 

 off for use. At ordinary temperatures, the 

 acid thus prepared has a faint, pleasant odor, 

 like that of geranium-leaves. 



TJie Prevention of Putrefaction. Dr. F. 

 Grace Calvert reported to the Eoyal Society 

 in February his laborious investigations of the 

 relative power of various substances to pre- 

 vent putrefaction, and also to develop proto- 

 plasmic and fungus life. To carry out his ex- 

 periments, small test-tubes were thoroughly 

 cleansed, and heated to dull redness. In each 

 were placed 26 grammes of a solution of albu- 

 men, containing one part of white of egg and 

 four parts of pure distilled water, and to this 

 w:ts added y.-^nnr, or 0.026 grammes of each of 

 the substances whose action he desired to 

 study. The operation was kept up for periods 

 ranging from 39 to 80 days, in a room the tem- 

 perature of which varied from 12.5 C. to 

 15.5 C., and each day a drop was taken from 

 each of the tubes, and examined with a mi- 

 croscope having a magnifying power of 800 

 <li;iiiicters. In order the better to show the 

 influence of the antiseptics used, he examined 

 two specimens at the same time, one of which 

 was kept as above described, and the other in 

 tin- ojK-n air. A marked difference was ob- 

 served in the result, the one kept in the open 

 air becoming Impregnated with animal life in 

 !<-, than half the time required by the other, 

 while as many vibrios were detected in the 

 former class <>t' tubes in 6 days as were devel- 

 oped in .0 days in the latter. Over 30 sub- 

 stances, among the acids, alkalies, phosphates, 

 sulphocarbolates, and chlorides, were experi- 

 mented upon. The following is a tabular state- 

 ment of the results, in which the substances 

 are grouped according to their chemical na- 

 ture : 



Dr. Calvert also undertook a series of experi- 

 ments, substituting gelatine for albumen, con-, 

 tinuing these for a period of 47 days. Vibrios 

 appeared in 2 days in the standard gelatine so- 

 lution, and bacteria after 4 or 5 ; and, during 

 the whole time of the experiment, life was 

 far more abundant than in the albumen solu- 

 tion. A distinct putrid smell was emitted after 

 26 days. With bleaching-powder, it took 20 

 days for life to appear, instead of 7 as in the 

 case of albumen, while at no time during the 

 29 days which remained was life abundant. 

 No putrid odor was emitted, but a mouldy one 

 could be detected on the thirtieth day. With 

 chlorine solution, vibrio-life was only observed 

 after 40 days, no putrid or mouldy smell 

 being given off at any time. Arsenious acid 



