1917] Mitra: Toxic and Antagonistic Effects of Salts on Wine Yeast 89 



and NaCl at .001M, i.e., 18 millions. But in combination the two salts 

 permit the highest growth of 29 millions per c.c. at .4M and .06M 

 respectively. 



The antagonism between these two salts in the case of yeast is 

 found very distinctly at both ends of the curves. For example, .1M 

 NaCl alone shows a growth of scarcely more than one million, while 

 in combination with .1M MgCh it shows over 17 millions, or 17 times 

 as much. On the other hand, .8M MgCL alone allowed a growth 

 of about SVo millions, while in combination with .01 ^NI NaCl the 

 growth was increased to about lS 1 /^ millions, or about twice as 

 much. 



In comparison with these results, a number of cases dealing with 

 the effects of combinations of MgCb and NaCl on plants, animals and 

 bacteria are cited below. 



(a) Plants. — Osterhout 5 found a distinct antagonism between the 

 two salts with the growth of a fungus (Botrytis cinerea). He found 

 that 15.M NaCl alone was very toxic, but that when this concentration 

 of NaCl was combined with .4 M MgCl, the toxicity was much re- 

 duced. He also found with wheat that neither NaCl nor MgCL at 

 .12M alone allowed root development, but in a combination in the 

 proportion of 100 c.c. NaCl to 75 c.c. MgCl 2 the root developed very 

 well. The same investigator obtained a negative result with green 

 algae. 20 



Kearney and Cameron 8 with Lupinus albus and Mcdicago sativa 

 have shown that the addition of MgCL to NaCl raised the tolerance 

 of these plants to the latter 3-10 times. 



(b) Animals. — Loeb 12 with Fundulus has found that in a mixture 

 of 98 c.c. 5/8n NaCl and 2 c.c. 10/8n MgCL all the eggs develop 

 embryos, while the same salts alone at the same concentration are 

 extremely toxic. Even an equal proportion of the two salts in the 

 same concentration allowed about 75 per cent of the embryos to de- 

 velop. He also found a similar antagonism with a sea urchin (Ar- 

 bacia) and a jellyfish (Poly orchis). 



Lillie 6 found that with the larvae of Arenicola the ciliary move- 

 ment continued for a time when he added 10 c.c. MgCb (10/8n) to 

 90 c.c. NaCl (5/8n), while the same concentrations of NaCl alone 

 would stop it immediately. Matthews with Fundulus found an an- 

 tagonism between the two salts. 



Ostwald, 13 however, with fresh-water Grammarus obtained con- 

 trary results. In this case a combination of the two salts was found 



