MILKY JUICE OF LETTUCE. 
209 
As the plant with which we are now engaged, is only a 
variety of that which furnishes the extracts of lettuce employed 
in pharmacy, it must, I think, be admitted, that the lettuce 
juice obtained by me, has a great resemblance to, if not perfect 
identity with lactucarium. Now, from the characters which 
I have assigned to this product, it is plain that it differs essen- 
tially from the thridace, and that it has been erroneously 
confounded with it. In fact we know that the thridace pow- 
erfully attracts humidity from the atmosphere, which is 
attributable to the large proportion of deliquescent salts con- 
tained in it; that its taste is ordinarily saline and extractive, 
instead of being bitter, and that its smell is not virose. The ne- 
cessity of establishing a distinction between these two 
medicines has already been pointed out by M. Chevallier, but 
it is really founded in facts, since Drs. Cox, Bidault de Villiers 
and Dumas, have made their experiments upon the lettuce 
juice (exudation) which they named lactucarium, and Dr. 
Frangois has experimented with the extract obtained by 
expression, and to which he has given the name of thridace. 
It is surprising, that after such a distinction has been made, 
several formularies should state that the thridace is prepared 
with the juice of lettuce obtained by incision; this is an in- 
accuracy, which I have thought it necessary to point out, 
since it has the tendency to lead the physician into error, as 
to the chemical and therapeutic effects of this medicine, and it 
may lead him, in some cases, to suspect the honesty of the 
pharmaceutist. 
Journal de Pharmacie. 
