Compounds of Albumin and Myosin. 309 
the mixture was made as near neutral as possible with dilute sodium 
carbonate and the compounds then filtered and washed thoroughly 
with water. The copper in this series was determined simply by 
ignition. 
Series VIII. 
With CuSO,. 
No. Am’t sub. taken. Wt. CuO. Per cent, Cu. 
la 0:4273 gram. 0.0068 gram. 1:26 
b 0:3867 0:0063 1:29 
2a 0°3167 0:0049 1°23 
b 0)°3535 0-0052 1:18 
3a 0°2418 0°0080 1:00 
b 0:3079 0-0089 1:00 
4a 06210 0:0188 1:78 
b 0:7091 0:0158 1:78 
The results plainly show no appreciable difference in the composi- 
tion of the albuminate under this change in the conditions, unless in 
No. 4 where a larger amount of copper is found than usual. It is our 
opinion, however, that the small amount of acid liberated by the re- 
action is not sufficient to cause any especial change in the character * 
of the albuminate; neither, probably, does very dilute sodium carbon- 
ate in itself change the substance to such an extent that on neutrali- 
zation it is not precipitated in nearly its original form, or at least that 
the action in this case is not any greater than that produced by water 
alone. In fact we are much inclined to the view that the long continued 
action of water will gradually but surely affect the composition of the 
albuminate, and that doubtless the change in the composition of the 
compound noticed in our experiments on solution of the substance in 
sodium carbonate and reprecipitation is due to the combined action 
of the alkaline fluid and of water. Harnack states that week-long 
treatment of the freshly precipitated albuminate with water will 
gradually cause dissociation of the compound, but that it can be easily 
and thoroughly washed without any decomposition whatever. 
Our experience, however, leads us to question the correctness of 
this view. Ordinarily, it has taken us an entire day to completely 
wash the freshly precipitated albuminate, so that the wash-water 
should give no reaction whatever for copper or albumin. In precipi- 
tating the albumin solution with cupric sulphate, the albumin never 
appears to be completely precipitated and at the same time, as Har- 
nack has observed, it is necessary to add more than the proportional 
