24:6 DIGESTION. 



To Blondlot belongs the rare merit of having been one 

 of the first, if not the very first, to propose and execute an 

 experiment by which the normal gastric juice could be ob- 

 tained in quantity from a living animal. In his first analy- 

 sis of the fluid thus obtained, he denied the existence of any 

 acid principles except the biphosphate of lime. This view he 

 holds at the present day ; and notwithstanding the elaborate 

 researches of the most distinguished physiological chemists, 

 in all of which a free acid of some kind has been recognized, 

 still ardently defends his original position. The question of 

 the existence in the gastric juice of the acid phosphate of 

 lime, to the exclusion of free acids, may be discussed in a 

 few words. 



Assuming that the gastric juice contains a free acid, a 

 view which the arguments of Blondlot fail to disprove, the 

 question arises whether the biphosphate of lime may not also 

 exist in this fluid. On this point there can be no doubt. 

 All the modern analyses of the gastric juice give the phos- 

 phate of lime as one of its constituents ; and Blondlot justly 

 remarks that it is strange to see, in certain analyses, the 

 neutral phosphate of lime and hydrochloric or lactic acid put 

 down as existing together, as though the phosphoric acid 

 were able to retain the two equivalents of the base in the 

 presence of either of these two acids. 1 The fact is, that basic 

 phosphate of lime (3CaO,PO 5 ), a salt insoluble in pure water, 

 but soluble in acid solutions, is invariably decomposed in the 

 presence of acids as powerful as the hydrochloric or the lac- 

 tic. It then loses two equivalents of the base, and is trans- 

 formed into the acid phosphate (CaO + 2HO,PO & ). 



After having discussed the question of the existence of 

 the biphosphate in two elaborate memoirs, one published in 



de Chimie, Paris, tome viii., p. 604), it is only stated that the acid reaction of the 

 gastric juice is not due exclusively to the biphosphate of lime, as was recently 

 advanced by Blondlot, and the existence of this principle is nowhere positively 

 admitted. 



1 BLONDLOT, Nouvelles Recherches sur la Digestion. Journal de la Physiologic^ 

 Paris, 1858, tome i., p. 310, note. 



