VOL. LXXxJ PHILOSOPHICAL TRANSACTIONS. 7ll 



companied with a peculiar odour more highly fetid and offensive than that which 

 is emitted by other malignant ulcers. 



Apprehending that some light might be thrown on the nature of cancerous 

 diseases, by inquiring into the properties of this substance, Dr. C. procured a 

 portion of it from a patient who had for several years been afflicted with a cancer 

 in the breast. Having diffused it through pure water, he divided it into 3 parts, 

 which were put into small glass vessels. To one of these he added a solution of 

 vegetable fixed alkali ; to the 2d, a little concentrated vitriolic acid ; and to the 

 3d, syrup of violets. By the vegetable fixed alkali no sensible change was pro- 

 duced: on the addition of the vitriolic acid, the liquor in the 2d glass acquired a 

 deep brown colour, a brisk efliervescence took place, and at the same time the 

 peculiar odour of the cancerous matter was greatly increased, and diffused itself 

 to a considerable distance through the surrounding air. The syrup of violets 

 communicated to the liquor in the 3d glass a faint green colour. The cancer- 

 ous matter used in these experiments had a brownish cast. It had been imbibed 

 by cotton, and kept for some days before the trials were made. 



Mr. Geber has shown, that animal substances on their first putrefaction do 

 not effervesce with acids ; that after the process has continued for some time, a 

 manifest effervescence takes place; and that this effect again disappears before the 

 putrefaction has ceased. Suspecting that the effervescence in the preceding ex- 

 periment might have arisen from a change which the matter underwent, in con- 

 sequence of its having been kept some days before the trial was made. Dr. C. 

 repeated the experiment with a portion of reddish matter recently obtained from 

 a cancerous penis. On the addition of the acid, the liquor, as before, acquired 

 a brown colour, its fetor was much increased, and a manifest effervescence took 

 place, though it was not so considerable as in the former instance. A portion of 

 the same matter diffused through distilled water communicated a blue tinge to 

 tincture of litmus, and a greenish cast to syrup of violets. It is proper to observe, 

 that when syrup of violets was mixed with portions of cancerous matter from a 

 variety of different subjects, the change produced was in some cases scarcely per- 

 ceptible ; but in every instance the presence of an alkali was detected by dipping 

 into the matter a slip of paper that had. been previously tinged blue by tincture of 

 litmus, and afterwards slightly reddened by acetous acid. The red colour was 

 invariably in the course of a few minutes abolished, and the blue restored. 



The cancerous matter, as has been already remarked, acquired, on the addi- 

 tion of the vitriolic acid, a brown hue. It is well known, that this acid, when it 

 is highly concentrated, communicates a brown or black colour to all animal and 

 vegetable substances. Being desirous of learning whether the change which took 

 place on the addition of the acid to the cancerous matter in this experiment, was 

 different from that which would be produced by the same acid in other animal 



