TRANSACTIONS OF THE SECTIONS. 39 
Caron’s experiments, and can fully confirm his results so far that, when copper is 
fused in a rapid stream of hydrogen and in a graphite boat, the copper is not 
vesicular, but when fused in a glazed porcelain boat, there are cavities in the 
. . . sh 
copper. Supposing, as M. Caron does, that hydrogen is soluble in melted copper, 
it 1s difficult to explain how this solubility is diminished to such an extent as not 
to be appreciable when the not glazed vessel is used. Further, there is no doubt 
(for it is an experiment that has been repeated many times) if copper be fused with a 
layer of charcoal over it, and a rapid current of hydrogen be bubbled through it, 
no trace of the vesicular structure is visible. From the experiments they have 
already made on the subject, the authors feel no doubt that the cavities in the 
copper are owing to a decomposition of the glaze; for they find that the glaze is 
always much acted on by the copper, that the cavities are always in the lower 
part of the ingot where it is in contact with the porcelain, and that the copper, 
istead of being vesicular throughout its mass, is very dense and tough, the 
cavities full of crystals. What the decomposition is which takes place, and how 
the gas comes to be eliminated in this way, it will take further experiments to 
explain, but the authors have no hesitation in saying that they do not believe 
hydrogen is dissolved at all by melted copper. 
On Paraffin, and its Products of Oxidation. 
By Dr. HE. Mevsen and C. Havewron Gri, 2.0.8, 
Paraffin, on being submitted to the prolonged action of dilute nitric acid, or of 
potassic dichromate somewhat diluted, and sulphuric acid, becomes gradually 
oxidized, and yields a number of fatty acids, the highest term of which is cerotic 
acid, C*7 H4 O*, and the lowest acetic acid. The oxidation of nitric acid also gives 
rise to the formation of succinic and anchoic acids, owing to a secondary action 
of the oxidizing agent on the cerotic acid, formed by the first oxidation of the 
araiin. 
. The fatty acids which are formed by oxidation of the hydrocarbons are sepa- 
rated from unaltered paraffin by converting them into soda soaps, and dissolving 
these out from the paraffin by dilute alcohol. They are then separated by Heintz’s 
method of partial precipitation, the cerotic acid being finally obtained in a pure 
state by repeated crystallization from a mixture of alcohol and ether. 
The paraffin used melted at 56° C., but could be separated into-portions, melt- 
ing higher and lower, and was therefore a mixture of various hydrocarbons. It 
would not combine directly with bromine, though its hydrogen was easily re- 
placed by that element. It formed no compound with sulphuric acid, either fuming 
ormonohydrated. Fyrom all which experiments, the authors concluded that parattin 
is a mixture of various hydrocarbons, of the series C*H2+2, and that in the 
sample employed there was one term of the series having a carbon condensation 
not lower than equal to C*’, 
On a Physical Property of two Coloured Compounds. 
By Dr. Evwarp Mevstt. 
One of these compounds, consisting of mercuric iodide with argentic iodide, is 
obtained by adding argentic nitrate to a solution of mercuric iodide in potassic 
iodide. A yellow precipitate is formed, which, well washed and dried at a low 
temperature, turns instantaneously red when exposed to a temperature above 50° C. 
The other compound, consisting of mercuric iodide with cuprous iodide, is pre- 
pared in the same manner, with the difference of cupric sulphate being added 
instead of argentic nitrate. At first a greenish-white precipitate is obtained, 
which, when shaken and heated, darkens, gives off iodine and turns red. The 
latter precipitate is as sensitive as the silver compound, and rise of temperature 
causes it to turn black. 
Both colours, allowed to cool, return to their original tint, an experiment which 
may be very often repeated with the same substance. 
Besides these two new iodine compounds, the author has found corresponding 
ones containing lead, gold, &c. 
