1917] Mitra: Toxic and Antagonistic Effects of Salts on Wine Yeast 83 



From both table 6 and the curves in figure 6 it is evident that 

 there is a distinct antagonism between these two salts. For example, 

 in the experiments with simple salts MgCl 2 alone at .8M concentration 

 allowed the growth of yeast cells up to only 8 1 /. millions, but in com- 

 bination with .01 M CaCL the growth was increased up to 12% millions, 

 i.e., 50 per cent increase. Similarly, .6M CaCL alone allowed an 

 increase to about one millions, and, with the addition of .01 MgCL, 

 an increase to 5y 2 millions, showing 5 l / 2 times more growth. Tim 

 highest number in MgCL alone was 26y 2 millions at .1M, and in CaCL 

 alone 19 millions at .01M concentration. In this binary combination 

 the highest number was obtained at G, the point where .1M MgCL and 

 .18M CaCL were combined with a ratio of about 2:1. 



For purposes of comparison let us now consider the results obtained 

 in similar experiments with these four salts on plants, animals, and 

 bacteria. 



(a) Plants. — Kearney and Cameron 8 found a distinct antagonism 

 between Mg and Ca ions for higher plants. In their experiments witli 

 leguminous plants Lupinus alius and Medicago sativa they found that, 

 for a combination of these two salts, the plants show about five times 

 as much tolerance as for the salts separately. The plants also dis- 

 played a remarkable degree of tolerance when MgS0 4 was used in- 

 stead of MgCL, thus showing in addition the relative difference be- 

 tween different anions of the same salt. 



Loew and his pupils, 10 ' 18 in their experiments with lower plants 

 (Spirogyra), have found a strong antagonism between Mg and Ca 

 ions. 



(&) Animals. — Loelr with sea urchins (blastulae and gastrulae) 

 found that a mixture of MgCL (10/8n) and CaCL (10/8n) will allow 

 them to swim for about forty-eight hours, while each of the salts 

 singly at the same concentration is extremely poisonous and kills the 

 animals. The same investigator 15 working with a jellyfish (Polyor- 

 cJiis) has shown that the addition of a small quantity of CaCL to a 

 mixture of NaCl and MgCL favors the normal, rhythmical contrac- 

 tions, while MgCL alone stops them altogether. Contrary to the 

 above results, Loeb 1 - in his experiments with frogs has found thai a 

 combination of Mg and Ca ions completely inhibits the rhythmical 

 muscular contractions. This has been corroborated by Anne Moore, 7 

 in her experiments with the contraction of the Lymph hearts of 

 frogs. 



Lillie' 5 has found that the ciliarv movement of the larvae of 



