VOL. LXXX.] PHILOSOPHICAL TRANSACTIONS. 715 



avoid concluding, that this phenomenon arose from an union between the acid 

 and alkali, in consequence of which the odoriferous principle was extricated by a 

 superior attraction. This conclusion will be confirmed by experiments to be re- 

 cited in the sequel, which prove, that the volatile alkali is capable of entering into 

 a chemical combination with the aerial fluid contained in the matter of cancer. 



Of the air extricated from cancerous matter, and from other animal substances^ 

 by distillation. — A portion of matter from a cancerous breast was diffused through 

 distilled water, and introduced into a small coated glass retort, which was 

 gradually exposed to heat in a sand bath till the bottom of the retort became red- 

 hot. The neck of the latter was introduced below an inverted jar filled with water, 

 and a quantity of air was received in the jar^ which was found to consist of the 

 common air contained in the retort. Two measures of it, mixed with one of 

 nitrous air, occupied the space of a little less than 2 measures. This portion of 

 air was strongly impregnated with the peculiar smell of the cancerous matter. 

 The heat continuing to increase, the water began to boil, and a large quantity of 

 aqueous vapour arose ; which, as soon as it came into contact with the common 

 air, produced a white smoke. The smell now perceived was similar to that of 

 fresh animal substances when boiled. The aqueous vapour in this part of the 

 process was not mixed with any permanently elastic fluid. 



When the greater part of the water was evaporated, the jar containing the first 

 portion of air was removed, and the neck of the retort was introduced beneath an 

 inverted vessel filled with mercury. Soon after this, a considerable quantity of 

 air, having a fetid smell similar to that of burned bones, was extricated. This 

 aerial fluid was mixed with a yellow empyreumatic oil. A portion of it being 

 agitated with water was found to be partly imbibed by that fluid ; and nitrated 

 silver, dropped into the water thus impregnated, produced a reddish precipitate. 



One measure of the air, obtained in the foregoing experiment, being mixed 

 over mercury with an equal bulk of alkaline air, the volume of the mixture was 

 found gradually to decrease ; and, at the end of 3 hours, the air in the 

 tube occupied the space of only 1 measure and -j^. An oily deposit was 

 now made on the inner surface of the tube. At the expiration of 8 days, 

 the interior surface of the tube was covered with slender films, which had 

 a yellowish cast, and which were irregularly spread on it. The upper surface of 

 the mercury within the tube was corroded ; in some places it had a reddish 

 burnished appearance ; in others, it was changed into an ash-coloured powder, 

 interspersed with brown spots. The tube was now removed from the mercury, 

 and the air that remained in it had a strong fetid smell, resembling that of burnt 

 bones. 



It has been already observed, that before the water was entirely evaporated, 

 the vapour had lost the odour of the cancerous matter, and had acquired that of 



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