INFLUENCE OF POISONS ON PKOTOPLASM, ETC.— HARRIS. 101 



No (li)iil)t v>'ry larj^e draughts of alcohol do inhibit p 'psiii by 

 precipitatiuii; it and so throwing it out of the sphere of chemical 

 activity (solution); but we know quite well that both gastric 

 and intestinal digestion can proceed in the presence of notable 

 ([uantities of alcohol, .\lcohol is a poison both to protoplasm 

 anil to its cnzymic secretions, but it is more toxi(; to the former. 



As Ehrlich long ago insisted, a poison can exert its in- 

 fluence only so long as it unites chemically with the mole- 

 cules of the living protoplasm, the biogens; a substance that 

 cannot unite, even temporarily, with the living stuff cannot be 

 a poison: if it cannot get into relations with it, it cannot in- 

 fluence it. 



Xow it is abundantly clear that poisons do enter into 

 union with the living stuff; chloroform continues to be elimina- 

 ted by the breath for many hours after the anaesthetized 

 person awakes. It is, of course, by its more or less firm union 

 for the time being with the living heart-muscle that chloro- 

 form "acts" in high doses so profoundly as a depressant of tha 

 cardiac myoplasm which it immobilizes so that the fibres 

 tend to die in diastolic atony. 



The respiration of tissues is their chief "vital" character- 

 istic, their taking in oxygen and giving out carbon dioxide — 

 internal respiration — - is of the essence chemically speaking of 

 tissue-life. 



In a rec-nit research Dr. H. J. M. Creightoii and I 

 studied more particularly the inspiratory aspsct of tissue 

 respiration, namely that carried out by th? reducing ferment 

 of the tissues hitherto called "reductase." 



The problem we put to ourselves wa-; this, — Do the al- 

 kaloids and other deadly narcotic poisons, substances which 

 kill animals in a very short time, act as inhibitants (poisons) 

 of "reductase" to anything like the same extent? The 

 answer in the negative was so unexpected that we tried to 

 verify it in every possible way. Our method was as fol- 

 lows — the tissue juice from a cat's liver crushed in physiolo- 

 gical (Ice) saline was mixed with a dilution of cat's blood in 



