1869.] Source of Free Hydrochloric Acid in the Gastric Juice. 391 



two discharges which have been mentioned. Nor is it difficult to find a 

 reason for the rest which follows the tetanus when cathelectrotonus is 

 established, and the momentary contraction which happens when cathelec- 

 trotonus passes off. The rest which follows the tetanus under these cir- 

 cumstances is intelligible ; for the cathelectrotonus may be supposed to 

 do away with the power of responding to the action of the salt; and 

 the momentary contraction which happens when the cathelectrotonus 

 passes off is intelligible also ; for/ according to the premises, the cessation 

 of the state of electrotonus implies the cessation of a state which counter- 

 acts that action of the salt which causes contraction. Moreover, it is intel- 

 ligible enough that there should be tetanns after anelectrotonus, and 

 momentary contraction only after cathelectrotonus, if the power of con- 

 tracting be impaired in the one case and preserved in the other. 



Nor is it otherwise with other experiments on electrotonus when care is 

 taken to eliminate what is fallacious. 



One and the same explanation, indeed, would seem to apply to the motor 

 phenomena connected with anelectrotonus and cathelectrotonus, and to the 

 motor phenomena connected with the inverse and direct currents ; and this 

 explanation is to be found, as it would seem, in the workings, not of the 

 constant current, but of statical electricity. 



The electrotonic variations in the conductibility of nerve detected by 

 Professor von Bezold are reserved for future investigation. 



April 15, 1869. 

 Lieut. -General SABINE, President, in the Chair. 

 The following communications were read : — 



I. " On the Source of Free Hydrochloric Acid in the Gastric Juice." 

 By Professor E. N. Horsford, Cambridge, U. S. A. Communi- 

 cated by T. Graham, F.R.S. Received January 18, 1869. 



The long-disputed position of Prout that the gastric juice contains free 

 hydrochloric acid, was at length established by C. Schmidt, who, in an 

 absolute quantitative analysis of the juice, found about twice as much hydro- 

 chloric acid as was required to neutralize all the bases present. The pro- 

 longed discussion of this subject (now since 1823) has brought to light, 

 through the researches of Lassaigne, Tiedemann and Gmelin, Berzelius, 

 Blondlot, Claude Bernard, Schwann, and numerous others, the unmistake- 

 able evidence of the presence of lactic acid and of acid phosphates in the 

 gastric juice, which latter might or might not be due to the presence of 

 lactic or hydrochloric acid. A point of special interest to the chemist and 

 physiologist still remained, and was this : 



2 g 2 



