IN Mixep SoLurions 393 
series of graded concentrations, an inspection of the tables shows 
that in general little, if any, diminution in the toxic action of the 
copper follows, This seems to indicate that magnesium is not 
able to diminish the poisonous action of the copper under the 
conditions present. 
When to copper chloride, calcium chloride is added in the 
proportion of 2/128, a decided decrease in the killing power of the 
copper is seen. When to copper chloride, sodium chloride, 12/16, 
is added, a strikingly reversed situation appears. Not only is the 
harmful action of the copper not diminished, but the mixture seems 
to be slightly more poisonous than the simple copper solution or 
TABLE III 
MIxepD SotuTions. HEAVY METAL AND LIGHT METAL. COMMON ANIONS. AVERAGE 
GROWTH-RATES IN MILLIMETERS 
Concent. of | CuSO, + CaSO, | CuCi, + MgCl, | CuCl, | CuCl, | AgNO, Hecl,, | ZnSO, 
olution | Ee es Rien, ake one 
of ney CaSO, | CaSO, | CaSO, | MgCl, | MgCl, { MgCl, | CaCl, | NaCl | KNO, CaCl | CaSO, 
see | m|t44 mias6 | mel5tz |} me] a8 } m 256 m| ste melxas _ mix6 | m/256 2 | mej256 
m|2048 | | 0.0 0.0) | ee 33-5 
mi4096 | 0.0| 0.0| 0.0 | 0.0 | 39.0 
m/8192 | 0.0 | 0.0 Ee RO St ; a0 0.0 | 37-5 
m/$6384). 3.0 |. 3.04 1.5 | 20) 20} 20] 20). 0.0} | tol ae 
m/32768 | 8.5 | 7.0 55: Pe 46 10} 6.0 | G0 1045 2 
m(65536 | 14.0 | 17.0 | 14.0} 40] 40] 30) 105) 05) 3.0) 80 
m/t31072| bk <¥O.5 | §.0 | 5.0, 10 5.0 | 
Check in| 12.0 | 11.0 | 11.0 | 10.0 | 14,0} 12.0 | 14.5 | 12.0 IE5 12.0 | 13.0 
water | 
Check in| 29.0 | 26.5 | 260) 401 90/ 45) 200 re mod a ate 
Solution 
of Light | | 
Metal | | 
the simple sodium solution. This would seem to indicate that to 
the poisonous action of the copper that of the sodium chloride 
itself is added. 
When to a solution of silver nitrate a solution of potassium 
nitrate, 72/256, is added, no very marked change in the action of 
the heavy metal is noticeable, the growth-rate coinciding approxi- 
mately with that seen in the solution of. the pure silver salt. 
What difference there is seems to be in the direction of greater 
toxicity. 
When to mercuric chloride, calcium chloride, #/256, is added 
