Nomis] HARDENING REAGENTS. I51 
In the same way the addition of } its volume of alcohol to 
the bichromate of potash solution, reduces the percentage of 
increase, as follows :— 
TABLE 22. 
Influence of 24% solution of bichromate of potash to which } its volume of 95% 
alcohol has been added. 
TimeE.—Days. PERCENTAGE INCREASE, 
I.I 16.6 
2.2 21.5 
3.9 23.6 
5-9 25.5 
12.9 26.4 
32.0 28.2 
In this connection it is of interest to note that the per- 
centage of the bichromate of potash solution is effective in 
restraining the increase in weight even in combination with 
alcohol, Tables 23, 24. In these latter tables we are dealing 
with entire encephala in which the pia is intact, and so it 
happens that in Table 23, the increase in weight under the 
2$% bichromate of potash, is less than in the Table 22 just 
given, where hemiencephala are employed. 
TABLE 23. 
Observations on two encephala in a solution of 2$% bichromate of potash plus 4 
its volume of 95% alcohol. 
PERCENTAGE INCREASE AFTER 75 Days. 
19.2 20.9 
TABLE 24. 
Observations on four encephala after 75 days in a solution of 2% bichromate 
of potash plus } its volume of 95% alcohol. 
PERCENTAGE INCREASE. 
24.7 24.7 24.9 26.1 
When 4% of copper sulphate is added to the solution and 
the specimens are kept at 38° C., we get the combined action 
of a high temperature and the copper sulphate as exhibited in 
Table 25. 
The period of loss of weight in these cases follows rapidly 
on the attainment of the maximum. 
