REPORT ON CHEMISTRY. 
437 
4°. Silicic acid and the silicates, and the same after heating 
to redness * * * § , 
5°. Antimoniates and antimonites, and the same salts after 
heating to redness f. 
6°. The two states of the acid and oxides of tungsten. 
• •• 
7°. Telluric acid J (T) and oxide of tellurium in their two 
states. 
8°. The soluble and insoluble cvanuric acids § (Cy + 2 O + H). 
9°. The cyanic and fulminic acids (Cy + O). 
10°. Oil of wine, and Faraday’s light liquid carbo-hydrogen 
(4 C + 4 H) §. 
11°. The pyrotartaric and pyroparatartaric acids? || 
12°, The two states of the phosphate of copper. 
13°. The two states of the bisulphuret of mercury. 
14°. The two states of phosphuretted hydrogen,—that which 
inflames, and that which suffers no change when mixed with 
atmospheric air,—shown by Rose to have the same composition. 
To these might be added several other compound bodies, the 
second state of which is induced by mechanical agency only. 
Iodide of mercury is a beautiful example in which a slight scratch 
sets the atoms of the crystal in motion, and changes the colour 
from a sulphur yellow to a deep red. Chloride of lithium 
* The change which takes pjace in the silicates by heating has been long 
known;—the principle of Isomerism enables us now to explain it. See Mit- 
scherlich’s Lehrbuch der Chemie , i. pp. 393 and 426. 
The gadolinite is a fine example of a silicate undergoing this change. When 
heated it appears to burn, emits light, and becomes yellow, but undergoes no 
change in weight. 
t Antimoniate of copper prepared by the moist way is very easily decomposed 
by acids : but when heated in vacuo it glows all over without change of weight, 
and is converted into so intimate a compound that no acid will now decompose 
it. A similar change takes place in the antimoniates of cobalt and iron, and 
in some of the antimonites. Phosphate of magnesia when heated exhibits the 
same phenomena of emission of light and heat during its conversion into para- 
phosphate. 
* An account of this new acid and its properties will be given in another 
part of this Report. 
§ For the first of these compounds Berzelius proposes the name of Etherine, 
as being most probably the base of the ethers. 
|| I have inserted these two acids with an interrogation, as their isomerism is 
only probable. The two isomeric acids, the tartaric and paratartaric, when 
subjected to destructive distillation give each acetic acid an insoluble crystalline 
acid which sublimes towards the end of the process ; and a third acid, which 
from the former is crystallizable, and from the latter is incrystallizable and very 
volatile. It is these last two acids which are here meant. The crystallizable 
(pyrotartaric) has lately been examined and analysed by Dr. Gruner. 1 have 
commenced an investigation of the latter, by which the isomerism of the two is 
rendered probable; but my results are not yet in a fit state for publication. 
