IN MIxeD SOLUTIONS 395 
cium nitrate, #/164, is added, a similar situation results. In the 
case of solutions of mercuric chloride to which calcium nitrate has 
been added, we find no amelioration of the poisonous action of 
the corrosive sublimate, the growth being, if anything, less in the 
mixed solution than in that of the mercuric chloride alone. 
In view of what has been said, the question naturally arises as 
to the effect of non-electrolytes in solution with the heavy metals. 
In this connection but two compounds were studied: cane sugar 
and urea. Tables IV and V present the results obtained. It 
will be seen that in a solution of copper sulphate, 7/655 36, to 
which cane sugar in concentrations varying from to /16 has 
been added, the growth-rate in general increases as the concen- 
tration of cane sugar diminishes. The growth-rate is markedly 
greater in the solution of copper sulphate containing cane sugar 
varying in concentration from m/4 to m/16 than in the copper 
solution alone. This growth-rate was not a persistent feature, how- 
ever, since in all the mixtures except that containing cane sugar at 
the least concentration, 72/16, no growth took place in the second 
twenty-four hours. It appears, therefore, that when cane sugar is 
added in proper proportions, as inthese experiments, the poisonous 
action of copper is somewhat diminished. This is probably due 
to the formation of copper saccharate and a consequent iessening 
of the number of Cu ions.* 
As regards the effect of the addition of urea, 72/64, it appears 
that the inhibiting action of the mixed solution is greater than 
that of the simple copper salt, the addition of the urea seeming 
to increase the total poisonous action. 
CoMPLEX MIXTURES 
In order further to test the effect of additions of lighter metals 
to salts of the more poisonous elements, more complicated syn- 
theses were made. These were of two classes: one mixed solu- 
tion in which all of the salts present had a common anion; a 
second mixed solution in which the anion of the salt of the heavy 
metal did not appear in any of the compounds of the lighter 
* See Loeb, J., and Gies, W. 1. Weitere Untersuchungen iiber die entgiftenden 
Ionenwirkungen und die Rolle der Werthigkeit der Kationen bei diesen Vorgingen. 
Archiv fiir die ges. Physiologie, 93: 261. 1902. 
