190 Dr. F. Crace-Calvert on Prevention of Putrefaction. [Feb. 29/ 



the eases of chlorine and bleaching-powder. When used in the proportion 

 above stated they do not prevent the production of vibrio-life. In order 

 to do so they must be employed in excess ; and I have ascertained, by a 

 distinct series of experiments, that large quantities of bleaching-powder are 

 necessary. I found that part of the carbon was converted into carbonic 

 acid, and part of the nitrogen was liberated. 



If, however, the bleaching-powder be not in excess, the animal matter 

 will still readily enter into putrefaction. The assumption on which its 

 employment as a disinfectant has been based, namely, that the affinity of 

 the chlorine for hydrogen is so great as to destroy the germs, is erroneous. 



The next class to which I would call attention is the tar series, where 

 neither the carbolic nor the cresylic acid fluids gave any signs of vibrionic 

 or fungus-life during the whole eighty days during which the experiments 

 were conducted. 



The results obtained with sulphate of quinine, pepper, and turpentine, 

 deserve notice. None of them prevent the development of vibrio-life ; but 

 sulphate of quinine and pepper entirely prevent the appearance of fungi. 

 This fact, together with the remarkable efficacy of sulphate of quinine in 

 intermittent fever, would lead to the supposition that this form of disease 

 is due to the introduction into the system of fungus-germs ; and this is 

 rendered the more probable, if we bear in mind that these fevers are pre- 

 valent only in low marshy situations, where vegetable decay abounds, and 

 never appear to any extent in dry climates, even in the midst of dense 

 populations, where ventilation is bad and putrefaction is rife. 



The results obtained in the case of charcoal show that it possesses no 

 antiseptic properties, but that it prevents the emanation of putrid gases, 

 owing to its extraordinary porosity, which condenses the gases, thus* bring- 

 ing them into contact with the oxygen of the atmosphere, which is simul- 

 taneously condensed. 



The above results have been confirmed by a second series. 



A series of experiments was also undertaken, substituting gelatine for 

 albumen, and was continued for forty-seven days. 



Vibrios appeared in two days in the standard gelatine-solution, and bac- 

 teria after four or five; and during the whole time of the experiment, life 

 was far more abundant than in the albumen-solution. A distinct putrid 

 smell was emitted after twenty-six days. 



With bleaching-powder it took twenty days for life to appear, instead of 

 seven, as in the case of albumen ; while at no time during the twenty-seven 

 days which remained was life abundant. No putrid odour was emitted; 

 but a mouldy one could be detected on the thirtieth day. 



With chlorine-solution vibrio-life was observed only after forty days; no 

 putrid nor mouldy smell was given off at any time. 



The protosulphate of iron gave, with this solution, results quite different 

 from those with albumen, in which, it will be remembered, vibrios appeared 

 in seven days, and fungi after fifteen ; whilst with gelatine neither proto- 



