640 ANNUAL llECORD OF SCIENCE AND INDUSTRY. 



hasten decomposition when present in small proportion in 

 fluids containing organic matter. This is the case with 

 domestic soap-suds, spent lye, and all more or less alkaline 

 liquids. Ammonia, permanganate of jjotash, biborate of so- 

 dium among chemical waste substances, do not accelerate 

 putrefaction, but, at the same time, they do not retard it. 

 Soda, potash, nitrate and chlorate of potassium, and lime, are 

 especially vigorous as purifiers. Salt, saltpeter, and sugar, all 

 substances which preserve meat when used in large quanti- 

 ties, act as putrefiers when added in small percentage. 



Under tlie second head, Dr. Dougall came to the conclusion, 

 as the result of his experiments with solutions containing or- 

 ganic matter, that putrefaction and fermentation are not 

 identical processes ; that the former is more difficult to pre- 

 vent than the latter, which sometimes subsides into putrefac- 

 tion, though putrefaction rarely becomes intensified into fer- 

 mentation. The best antiseptics, in his opinion, are the acids, 

 since it is apparently impossible for marked putridity and 

 acidity to go together. Among these he especially mentions 

 chromic acid and benzoic acid, carbolic acid, indeed, only re- 

 tarding the appearance of the animalcules and fungi for a 

 time. 



The most important portion of Dr. Dougall's investigations 

 related to the relative antiseptic powers of difierent volatile 

 bodies, and here the chloride of lime appeared to be efficient 

 in nearly all cases. It was ascertained that nitrous acid, gla- 

 cial acetic acid, and hydrochloric acid are the most perfect 

 in their action ; and that next come carbolic acid, sulphurous 

 acid, and chloride of lime, the last being the best of the three. 

 But as the application of these substances was made under 

 very favorable circumstances, and much more concentrated 

 than it is possible to use them in practice, he concludes that 

 aerial antiseption is in most cases fallacious. A very curious 

 fact was developed in regard to the action of various sub- 

 stances upon vaccine lymph in preventing its activity car- 

 bolic acid, both in vapor and solution, as well as chloroform, 

 camphor, sulphuric ether, and iodine, not inte]-fering with this 

 activity. Lymph, exposed to the action of vapor of chloride 

 of lime, sulphurous, nitrous, glacial acetic, and hydrochloric 

 acids, was found incapable of producing its characteristic ef- 

 fect, however, from which Dr. Dougall concludes that these 



