No: 1.] HARDENING REAGENTS. 135 
with the fresh ones, it is to be concluded that this process of 
hardening adds slightly to the total solids. This amount 0.4% 
and 1.4% of the total fresh weight is equal to 0.21 and 0.75 
germs. The average quantity of fluid in the hardened specimens 
is about 50 c.c., which would contain nearly 1 grm. of the salt. 
To the solids found, the percentage of bichromate of potash 
in the solution bears the same relation. 
After 60 days in a solution of $% of bichromate of potash, 
the percentage of solids was found as follows :— 
TABLE 7; 
SERIAL NuMBER. PERCENTAGE OF SOLIDS. 
70 19.3 
7! 19.5 
72 19.1 
73 19-5 
AW CLACC Hee men Celie -Fits ten LO: 
When we consider Table 7, we see that a 1% solution of 
bichromate of potash reduces the quantity of solids slightly 
below the normal. 
The reduction in this instance must be the result of the ex- 
traction of the solids from the specimen by the solution. In 
Table 6, the increase in solids certainly comes from the salts, 
and we see that in these cases the increase in solids is less 
than is to be expected, if the fluid within the specimens con- 
tains the same percentage of salts as that surrounding it. 
That this percentage of salts increases with time, is also shown 
in this Table 6, but as yet we have no evidence to show to 
what extent the 2% solution of bichromate of potash extracts 
solids from the specimen, and we therefore cannot say to what 
degree the result obtained is a balance struck between oppos- 
ing processes. 
As the following Table 8 shows, the increase in weight is 
dependent to some degree on the compressing action of the 
pia on the specimen ; and in this connection the reaction of 
specimens with the pia intact and those with the pia slit, have 
been studied. Where the pia is slit the percentage of solids is 
greater. 
