Dr. Crawford’s Experiments on the Matter 
tongue and internal fauces, when venereal ulcers of the throat 
are waffled with a folution of corrofive fublimate. And hence 
alfo the dark tinge which is frequently communicated by ill- 
conditioned ulcers to poultices made with a folution of fugar of 
lead. The a&ion of the hepatifed ammonia likewife explains 
the reafon why the probes are frequently corroded when they 
are introduced into finuous ulcers, or applied to the furfaces of 
carious bones. To the fame caufe it is probably owing, that 
polilhed metallic veflels are quickly tarnilhed, when they are 
expofed to the effluvia of putrid animal fubftances. 
From the foregoing experiments it moreover appeals, that 
animal hepatic air imparts to the fat of animals recently killed 
a green colour ; that it renders the mufcular fibres iott and 
flaccid, and increafes the tendency to putrefaction. It is there' 
fore a feptic principle ; and hence it is extremely probable, that 
the compound of this fluid with volatile alkali, which is found 
in the matter difeharged by the open cancer, produces dele- 
terious effects : for although the mifehief in cancerous ulcers 
feems principally to depend upon a morbid action of the vef- 
fels, whence the unhealthy ftate of the matter difeharged by 
fuch ulcers is fuppofed to derive its origin, yet from the cor- 
rofion of the coats of the larger blood-vefiels, and the obftruc- 
tions in the contiguous glands, there can be little doubt that 
this matter aggravates the difeafe. The experiments recited 
above appear to prove, that the hepatifed ammonia is the in- 
gredient which communicates to the cancerous matter its putrid 
fmell, its greater thinnefs, and, in a word, all the peculiar 
.properties by which it differs from healthy pus. 
From thefe confiderations it was inferred, that a medicine 
which would decompofe the hepatifed ammonia, and deflroy 
the fetor of the animal hepatic air, without at the fame tune 
increafing 
