450 Messrs. Harden and Paine. Action of Dissolved [Oct. 17, 



slight difference is observable in the effect of concentrations ranging from 

 07 to 1-1 molar. 



Experiments made with other salts showed that the phenomenon described 

 for sodium chloride is a general one for all salts, both of inorganic and 

 organic acids. The following salts were all found to give positive results i 

 Chlorides of sodium, potassium, lithium, ammonium, magnesium, calcium, 

 and barium ; sulphates of sodium, potassium, ammonium, and magnesium ; 

 sodium salts of phosphoric, hexosephosphoric, arsenic, acetic, malic, citric,, 

 lactic, pyruvic, and glyceric acids. 



With the salts of organic acids, the possibility exists that these may 

 themselves be the source of the carbon dioxide. Neubauer (3) and Neuberg, 

 Hildesheimer, Tir, and Karczag (4, 5, 6) have, in fact, stated that some 

 races of yeast are capable of producing carbon dioxide from salts of lactic, 

 glyceric, pyruvic, oxalacetic, and many other acids. As this phenomenon is 

 accompanied by the disappearance of the acid in question, it can readily be 

 distinguished from that which forms the subject of the present paper. 



2. The Nature of the Effect Produced by Scdts on the Autofermentation of 



Yeast. 



It seemed advisable at the outset to ascertain experimentally if the- 

 increase in the rate of gas production were actually due to stimulation of the- 

 glycogenase, as was to be expected, or of the zymase. The sugar fermentation 

 of 1 grm. of yeast immersed in molar sodium chloride gave only l - 7 c.c. of 

 carbon dioxide per five minutes, as against 4-1 c.c. in the case of a water 

 control. The action of the zymase is therefore inhibited rather than 

 enhanced by this treatment. The increase in the rate of autofermentation' 

 would accordingly seem to result from a more efficient working of the 

 glycogenase. 



This might be due to one or more of the following causes : — 



(1) To some specific action of the salt employed. 



(2) To a concentration within the cell by removal of water as a result of 

 plasmolysis. 



(3) To removal from the cell of some substance or complex which has an 

 inhibitory or controlling action upon the rate of glycogen fermentation. 



(4) To disorganisation of the cell, whereby the factor controlling the access 

 of enzyme to glycogen is in some way modified. 



(5) To "hormone" action of the substance on the lines suggested by 

 H. E. and E. F. Armstrong. 



(1) Specific Action. — In order that a specific action should be exerted, it is 

 essential that the agent should be capable of entering the cell. As regards 



