No. I.] HARDENING REAGENTS. 157 
For the solids the corresponding figures : — 
Mean for cortical gray substance = 14.73% 
Mean for white substance, cerebrum = 29.77% 
As is plain, the solids in the white substance are twice ad 
abundant as in the gray. We begin with the observations on 
the adult —all the brains being from persons more than 25 
years of age. Unless otherwise stated, 4 litres of fluid were 
always used. The letter (c.) after an entry in the table means 
as previously stated, that the fluid was changed, z.e. renewed 
at the time of the observation after which it stands. As in 
the case of the sheep’s brain, the pia was not removed. 
If a human encephalon without cutting in any way, be put 
in 2% bichromate of potash, the following is the result :— 
TABLE 34.— Brain XVIII. 
Female. Age, 4o years Death from pneumonia. In the hardening fluid 16 
hours after death. 2% solution of bichromate of potash. Encephalon intact. 
Fresh weight 1335 grms. 
Time. — Days. PERCENTAGE INCREASE. 
0.7 6.2 
120.0 235.2 
270.0 24.2 
It can be seen by consulting Tables 35 and 36 that sub- 
division of the encephalon, before putting it into the harden- 
ing fluid, is followed by a greater change in weight. 
TABLE 35.— Brain XIX. 
Male. Age,22 years. Death from phthisis. In the hardening fluid 11 hours 
after death. 2% solution of bichromate of potash. Encephalon subdivided. 
Fresh weight 1248 grms. 
Time. — Days. PERCENTAGE INCREASE, 
120 34 
The figures show clearly enough the influence of subdividing 
the encephalon on the subsequent reaction. In the larger 
number of the tables which follow, the changes in the sub- 
divisions of the encephalon are recorded separately. 
