TiCHBORNE — 0)1 Dissociation hy Heat of Compounds. 169 
The author also laid before the Academy the result of an examina- 
tion of some specimens of sugar beet, grown on the Glasnevin Model 
Farm. These specimens were treated as follows. A portion was cut 
from each root by planes passing through the axis. This was grated 
on a coarse grater, then steeped in spirit {G = -828), and pressed in a 
screw press. The residue was again treated with spirit, and pressed ; 
and this process was repeated. The expressed fluid, the spirit having 
been distilled off at low pressure, was made up to a known bulk with 
water, and filtered through animal charcoal, the first portion of the 
filtrate being rejected. The fluid thus obtained was examined in the 
way described above. The amounts of cane sugar in 100 grs. of the 
Yopt are as follow : — 
Total Weight of Root. 
lbs. 
oz. 
1 ... 
... 12-03 ... 
... 1 ... 
... 121 
2 ... 
9-56 ... 
... 1 ... 
... 14 
3 ... 
... 12-57 ... 
... 1 ... 
... 14 
4 ... 
... 12-60 ... 
... 2 ... 
5 ... 
... 11-62 ... 
... 2 ... 
7 
6 ... 
... 12-43 ... 
... 1 ... 
... 13f 
XXYIII. — Eepoet on the Moleculah Dissociation- by Heat of Com- 
pounds IN- Solution-. By Chaeles E. C. Tichboene, F. C. S., 
M.E.I. A., &c. With Plates XY. and XYI. (Science). 
[Eead April 24, 1871.] 
Paet I. — Inteoduction". 
M. Deville's researches upon the dissociation of compounds by heat, 
when converted into the gaseous condition, have brought prominently 
before us the antagonistic nature of thermal to chemical force. We 
find that the antagonistic action of these forces is manifested when we 
are dealing with compounds in the liquid condition, or in the so-called 
solutions" of solid substances. It is a commonly acknowledged idea 
that in such cases heat hastens and modifies chemical decompositions ; 
but how it modifies them ? and to what extent ? are questions which 
are seldom clearly defined. 
The main purport of this report is the application of such inquiries, 
as those mentioned, to the science of chemical geology. I may remark, 
that some of the hypotheses mentioned in the course of my Paper, are 
generally acknowledged, some indirectly accepted, and some emanate 
from myself. Similar remarks will apply to the phenomena observed. 
* The modifications of force are for convenience considered in this Paper as 
separate entities. 
K. I. A. TROC. — VOL. I., SER. II., SCIENCE. Z 
