■sili/ of California Publications in Agricultural Sciences [Vol. 3 



B. Experiments With Combinations of Salts — Antagonistic 



Effects 



The toxic effects of the single salts KC1, MgCl 2 , CaCl, and NaCl 

 upon a wine yeast, S. < llipsoidt us, have been shown in the first part 

 of this paper. The results of the study indicate that the reactions 

 of yeast differ from those of plants, animals or bacteria. This second 

 part of the paper gives the results of an investigation to ascertain the 

 effects of various binary combinations of the salts named upon the 

 same yeast. 



From the four salts, six combinations of two salts each are possible. 

 All of these were tested. Judging from analogous work of other 

 investigators with animals, plants and bacteria, it was expected that 

 these salts would exhibit mutually antagonistic action, i.e., that the 

 toxicity of one salt would be reduced by the presence of another and 

 that the total effect of two salts together would be less than the sum 

 of their individual effects. In some cases definite antagonistic effects 

 were found. In others antagonism was not so well defined. In a 

 few instances there was no antagonism shown. 



In the discussion of results, considerable space has been given to 

 the findings of other investigators because it was considered important 

 to point out how the effects on other organisms compare with those 

 on yeast. A few words on the development of the idea of antagonism 

 in binary combinations of salts will be of value as an introduction to 

 the data in this paper. 



Considerable work on the antagonistic effects of salts has been 

 done by Ringer, Locke, Howell, Loeb, Osterhout, Overton, Ostwald, 

 Loew, Lipman and others. That the poisonous effect of one salt is 

 reduced by the addition of another salt has been known for a long 

 time, especially among animal physiologists. In this matter we owe 

 a great deal of our knowledge to Loeb, whose investigations brought 

 forth a large number of unexpected results. It was he who first 

 developed the theory that the valences of metallic, ions have consid- 

 erable influence on their toxic and antagonistic effects, and that mono- 

 valent cations may be antagonized by bivalent, trivalent or tetravalent 

 but not by monovalent cations. His results show some parallelism 

 to the work of Linder and Picton.* This general statement does not 

 apply in all cases to plants, animals and bacteria, experimented upon 

 by various other investigators. Neither does it apply always to yeast. 



* Hober and Gordon, Beitr. zur chem. physiol., vol. 5, p. 432, 1904, cited bv 

 Osterhout. 22 



