_ ulcer, and to change the diseased surface of a sore already existing. = 
¢ Eee i ay in the frui 
he sour juice of these fruits consists either of the citric 
Po acids, or more frequently of a mixture of both.. The citric 
acid is that which is most largely employed, as it forms. chiefly the. 
acid juice of the orange and lemon, the two acid fruit, in gommen 
pee use, 
CLASS XV. —ANTACIDS. 
rACIDS are ‘remedies which obviate acidity in the ; 
Their action is purely chemical, as they merely combine with the — 
acic ‘present, and neutralize it. They are only palliatives, the ee 
ration of acidity being to be prevented by restoring the tone 
stomach, and its vessels. Dyspepsia and diarrhea are the disenaee 
in which they are employed. 
a 4 
CLASS XVI.—LITHONTRIPTICS. 
_Lrrnonteirtics are medicines supposed to be | 
ving urinary calculi, Their operation is entirely c 
The researches of modern chemists have proved, that 
culi, in general, consist principally of a peculiar animal acid, | 
the lithic or uric acid. With this substance the alkalies are 
of uniting, and of forming a soluble compound. = 
From the exhibition of alkaline remedies, the symptoms 
from a stone in the bladder are very generally alleviated ; an 
can be given to such an extent, that the urine becomes sensibly alka- 
line, and is even capable of exerting a solvent power on these concre- 
tions. Their administration cannot, however, be continued to 
extent for any considerable length of time, from the strong irritation — 
they produce on the stomach and urinary organs. The use, there-_ 
fore, of the alkalies as solvents, or lithontriptics, i is now scarcely av 
attempted ; ; they are employed merely to prevent the increase 
concretions, and to palliate the painful oral bebe Py, do, 
apparent! reventing the generation of lithic acid, or the sepa~ 
rae of ia Hadeye? the urine is thus rendered less irrita- . 
ting, and the surface of the calculus is allowed to become smooth. _ 
ih. 
CLASS: XVIL—ESCHAROTICS. 
. Seseiioeics are substances capable of dissolving animal matter; _ 
applied to the skin, they erode it, and to an ulcer, they remove € 
surface. They are employed to consume excresences, to 0) 
* ee i is entirely chemical. 
