286 
OPT GASTRIC JUICE. 
by Mr. Blondlot, encouraging me to profit by his obliging 
offer, I took up again the experiments made some years ago 
under less favorable circumstances, and which it may be use- 
ful to recapitulate. 
Mr. Valentin had offered to my learned friend Mr. Ma- 
gendie to repeat, in his presence, the experiments upon 
artificial digestion, by means of what was then called by 
Mr. Schwann, and since him, by Mr. Muller, pepsine. 
This substance, the discovery of which had fixed the 
attention of the savants of Germany, was supposed to be 
contained in a weak solution of hydrochloric acid which 
had been placed in the stomach of a calf during several 
hours. The experiments took place in the College of 
France; a stove of even temperature was employed, and 
several substances were tried, particularly muscular tissue 
and coagulated albumen, in the digestive liquid comparative- 
ly with acidulated water, for 12 hours. 
The examination of the results was made by Messrs. 
Magendie, Valentin, Poisseuille, several others, and myself. 
All the results were found negative; the meat remained 
hard and the albumen preserved the angular forms of all its 
fragments. Mr. Valentin attributed the want of success to 
the weakness of the acid used, which threw off less vapours 
than the one employed by Mr. Schwann. 
Upon these indications I made some new experiments, 
but found it impossible to obtain positive effects, or extract 
by Mr. Schwann's process, or others which I essayed, any 
principle to which could be assigned the special property in 
question. Having now the disposition of a normal gastric 
juice endowed with great energy, I hope to be more success- 
ful ; and in fact, from the first attempts in the direction 
which I had formerly followed in vain, I have succeeded in 
isolating a white or delicately amber colored substance, 
diaphanous, very soluble in water, easily dried, and so very 
active that it will disaggregate more than three hundred 
