ON ENZYMES AND LIVING CELLS 99 



The physiological balance of salt solutions first discovered 

 and investigated by Ringer, in the case of the frog's heart, has 

 been extended by Loeb to skeletal muscle and to marine organisms, 

 and shown to be a general law. 



In addition, Loeb made the most important discoveries that 

 cell division can be initiated and carried to an advanced stage 

 of development, in the unfertilised eggs of several organisms, 

 by variations in the saline conditions only ; that the conditions 

 requisite for fertilisation and cross-fertilisation vary with the 

 composition in inorganic salts of the medium, and with its reaction, 

 and that the rate of growth varies with the degree of alkalinity. 



These valuable results obtained by many independent observers 

 show the immense importance to the growth and activity of living 

 cells of their inorganic constituents, and this division of bio- 

 chemistry is rapidly acquiring an immense literature of its own. 



In such an action due to variation in inorganic salts, the writer 

 believes that the key will ultimately be found to the secret of 

 the cause of irregular cell division in the body, giving rise to 

 malignant growths. For the production of what must be described 

 as a pathological division in unfertilised eggs, and the production 

 of pathological cell divisions such as have been noted by Galleoti 

 by the action of inorganic salts such as the iodides, must be 

 problems of the same order as the causation of the ungoverned 

 and pathological divisions, often of very similar type, found in 

 malignant growths. 



As a general rule it may be stated that for the same enzyme 



the intensity of action of a^ given concentration of an alkali or 



+ 



acid varies approximately directly as the concentration in HO or H 

 ions, the effect of the other ion being only of secondary im- 

 portance. Thus in all cases free alkalies such as sodium or 

 potassium hydrate are many times more powerful than the cor- 

 responding carbonates in consequence of their almost complete 

 ionisation as contrasted with the low ionisation of the carbonates. 1 

 Again, ammonia, which is but feebly ionised (about -g 1 ^- of that of 

 sodium hydrate) has a correspondingly feeble destructive action. 

 The same holds in the case of acids, the effect here being mainly 



1 In deci-normal solutions sodium carbonate has only about 3 per cent, of 

 the concentration in hydroxyl ions found in sodium hydrate (Shields, Zeitsch, 

 f. physik. Chem., vol. 12, p. 167). 



