ME. T. g-eaham: OE" liquid dieeusion applied to analysis. 
189 
gravitation. It may therefore be not amiss to place here in a short tabular form the 
results observed of the diff usion of a few more substances, conducted in the same manner 
as the preceding. 
Table II. — DifFusion of 10 per cent, solutions for fourteen days. 
Number of stratum 
(from above downwards). 
Sulphate of magnesia, 
at 10°. 
Albumen, 
at 13° to 13°-5. 
Caramel, 
at 10° to 11°. 
1 
•007 
2 
•oil 
3 
•018 
4 
*027 
5 
•049 
6 
•085 
•003 
7 
•1.33 
•005 
8 
•218 
•010= 
•010 
9 
•331 
-015 
•023 
10 
•499 
*047 
•033 
11 
*730 
•113 
•075 
12 
1*022 
•343 
•215 
13 
1-383 
•835 
•705 
14 
1*803 
1-892 
1-725 
13 and Ifi 
3-684 
6-725 
7-206 
10-000 
10-000 
10-000 
The sulphate of magnesia was anhydrous. The albumen was purified by Wurtz’s 
method. The caramel was partly purified by precipitation by alcohol, as recommended 
by FeSmt, and further by other means which will again be referred to. It will be 
remarked that the diffusion of sulphate of magnesia exhibited above is very similar to 
that of sugar in a former Table, but is slightly less advanced. The similarity in diffusi- 
bility of these two substances had already been observed in the experiments of former 
papers. The fall in rate on passing from these crystalloids to the colloids tannin, albu- 
men, and caramel is very striking. The elevation in the liquid column attained by 
albumen or by caramel is moderate indeed compared with that of crystalline substances. 
Of albumen, which will be looked upon with most interest, no portion whatever was 
found in the seven higher strata. It appeared to the extent of O'OIO gramme in the 
eighth stratum, 0’015 in the ninth stratum, 0‘047 in the tenth stratum, 0T13 in the 
eleventh stratum. O' 343 in the twelfth stratum; while the great mass of this substance 
remained in the four lower strata. The diffused albumen did not appear to lose its 
coagulability, or to be otherwise altered. It will be seen immediately that the diffu- 
sion of sugar advances as much in two days as the albumen above in fourteen days 
(Table IV.). 
The diffusion of caramel is the slowest of all, and does not much exceed in fourteen 
days the diffusion of sugar in a single day. 
It was considered useful to possess examples of the progress of diffusion, in one or two 
selected substances, for successive periods of time, so as to exemplify the continuous 
progress of diffusion in these substances. Such a chronological progress of diffusion in 
