ME. T. GEAHAIVI OK LIQUID DIFrUSION APPLIED TO ANALYSIS. 
203 
Table XII. — Dialysis through Parchment-paper during twenty-four hours, at 10° to 15°. 
1 Ten per cent solutions. 
Diffusate, 
in grammes. 
Relative 
diffusate. 
Osmose, in 
grammes 
of water. 
Eelative 
osmose. 
Gum-arabic 
0-029 
♦004 
5-0 
•263 
Starch-sugar 
2-000 
-266 
17-0 
•894 
Cane-sugar 
1-607 
-214 
15-3 
•805 
Milk-sugar 
1-387 
•185 
15-0 
•789 
Mannite 
2-621 
•349 
17-6 
•926 
Glycerine 
3-300 
-440 
17-6 
•926 
Alcohol 
3-570 
-476 
7-6 
•400 
Starch-sugar (second experiment) 
2-130 
-284 
l6-8 
•884 
Chloride of sodium 
7-500 
1 
19-0 
1 
The experiments were all made through the same portion of parchment-paper, and in 
the order of the Table ; gum-arabic first, and chloride of sodium last. After every expe- 
riment the bulb was immersed in water for twenty-four hours, to purify the septum, 
before it was again used. The ditfusion of starch-sugar was repeated early and late in the 
series of experiments, ufith little change in the result, showing considerable uniformity 
in the action of the parchment-paper ; the first diffusate of starch-sugar being 2 grammes, 
and the second 2T3 grammes. Yet the parchment-paper had been in contact with 
water or some solution for a whole fortnight between the two observations referred to. 
A layer of animal mucus, taken from the stomach of the pig, 12 millimetres in thick- 
ness (10 grammes of humid mucus being spread over 0-005 square metre of surface), was 
applied, between two discs of calico, to the difiusion-bulb used above, the parchment- 
paper being first removed. 
Table XIII. — Dialysis through Animal Mucus during twenty-five hours, at 10° to 15°. 
Ten per cent, solutions. 
Diffusate, 
in grammes. 
Proportional 
diffusate. 
Osmose, in 
grammes of 
water. 
Gurn-arabic 
•023 
•004 
+ 29 
Starch-sugar 
1-821 
•360 
+ 7-6 
Cane-sugar 
1-753 
•347 
-I 4-6 
Milk-sugar 
1-328 
•262 
+ 7-1 
Mannite 
1-895 
•375 
-f- 5-0 
Alcohol 
2-900 
•573 
+ 7-2 
Starch-sugar 
1-765 
•349 
+ 7-0 
Glycerine 
2-554 
•505 
+ 7-5 
Chloride of sodium 
5-054 
1 
- 0-2 
The relative difiusibilities of the different substances present a considerable degree of 
similarity in the two Tables, and are equally analogous to the difiusibilities of the same 
substances observed in pure water. The intervention of a colloid septum cannot be said 
to have impeded much the diffusion of any of these substances except the colloid gum. 
The dialysis through parchment-paper of several other organic substances, both cry- 
stalloids and colloids, may be brought together, in comparison with the chloride of 
sodium as a standard. The larger osmometer bulb was used, and the parchment-paper 
2 f2 
