40 



Scientific Proceedings (31). 



with its nerve centers,^ and of (/^) gland extracts, which sometimes 

 raise blood pressure and often lower it (sometimes after a slight 

 previous rise), and (2) by the contradictory effects of some salivary 

 gland extracts on gastric secretion. All of this doubt will con- 

 tinue so long as we are compelled to deal with a complex mixture 

 of various substances in gland extracts and not with one pure sub- 

 stance of known composition. 



To this consideration belongs, also, the antagonistic phenomena 

 reported by Lilienfeld, Horowitz and Delezenne as occurring in 

 blood coagulation (positive and negative phase of coagulation). 

 This is explained by Lilienfeld and also by Delezenne by the 

 isolation from blood plates and leucocytes of two substances, one 

 of which they term " leiiconuclein" which favors coagulation, and 

 the other, " histon," which retards coagulation. Before the isola- 

 tion of these two substances the phenomenon of the positive and 

 negative phase during blood coagulation appeared paradoxical, and 

 the idea of a latent period of coagulation might have come to 

 many an experimentor. Just so with the latent period after chem- 

 ical stimulation of the glands ; it may be due to inhibitive sub- 

 stances in the gland extracts used, and it is possible that this delay 

 in bringing about the effect after chemical stimulation of the gas- 

 tric glands, may disappear with a clearer knowledge of the chem- 

 istry of the gland extracts, and a more accurate method of pre- 

 paring them. 



Besides the latent period of secretion, we must consider the 

 neutralization of the first acid secreted by the mucus present in 

 the stomach. Pawlow (" Arbeit, d. Verdauungsdrusen," /. c, p. 39) 

 calls attention to what he emphasizes as " Factum," namely, 

 " Even with a normal stomach and with a pure gastric juice 2§ per 

 cent, of its acidity can be lost through neutralisation by inuais." 

 How much more must this neutralization take place in a stomach 

 that, as Loevenhart states, gave " much dark mucus." The very 

 efforts of catheterization increases the mucus formation, and after 

 the submaxillary gland extract was injected, if it had any stimu- 

 lating effect at all (I am not prepared to state whether it had or 

 not) this much is sure, the mucus had to be neutralized before 



' This latter effect of adrenalin is not a purely chemical effect but a mixed effect of 

 nerve and chemical phenomena. One and the same chemically pure substance cannot 

 be claimed to contain both stimulating and inhibitive substances. 



