428 Intelligence and Miscellaneous Articles. 



'o 



of methylene is converted into hydrated formic acid, which change is 

 intended to be rendered clear by the following symbols: 

 & W, H< ON-0**C* H« O', H*0 + H« O'. 

 And thus it is remarked that by the theory of substitutions, as it is 

 termed, the pyroxylic spirit loses four volumes of hydrogen and gains 

 two volumes of oxygen. By the bye this theory of substitutions means 

 only, we presume, that when any compound parts with one of its ele- 

 ments and its place is supplied by another, both are in atomic quan- 

 tities; a necessary result of the doctrine of definite proportions. 



Chlorine acts upon pyroxylic spirit in the same way as upon alcohol, 

 but the action is less intense. Dissolve a pound of good chloride of 

 lime in water, put the clear solution into a retort, and add to it an 

 ounce of pyroxylic spirit. When heat is applied, impure chloroform 

 is obtained in the receiver j it is to be separated from the water, agi- 

 tated for some time with concentrated sulphuric acid, and then rec- 

 tified from barytes in fine powder. Chloroform thus prepared yielded 

 by analysis the same results as chloroform obtained from alcohol, 

 viz. 



Carbon 101 



Hydrogen 0-9 



Chlorine 89*0 



100- 

 Sulphuric acid when distilled with one fourth of pyroxylic spirit is 

 attended with phenomena perfectly resembling those of the distillation 

 of alcohol and sulphuric acid. 



FYom the commencement of the ebullition to the end of the action, 

 gas is abundantly liberated j this is a mixture of carbonic and sulphu- 

 rous acid gases, with an aethereal gas, which is not acid, and which dis- 

 solves entirely in water and burns like alcohol. To separate the acids 

 the mixed gases must be kept in contact with fragments of potash 

 for 24 hours ; then there remains the pure aethereal gas, or hydrate of 

 methylene, and which is to pyroxylic spirit what common aether is to 

 alcohol, that is to say, the bihydrate of methylene has lost half its 

 water to constitute the gaseous hydrate, just as alcohol loses half its 

 water to form common aether. It consists of 



1 atom m&hvlene 178*05 or 61*28 



* 1 atom water 112-50 — 3872 



290 55 100-00 



Hydrate of methylene is a colourless gas j it has an aethereal smell, 

 burns with a pale flame like that of alcohol. When cooled to 3° Fahr. 

 it does not liquefy j water at 64° dissolves about 37 times its volume, 

 and acquires an aethereal odour and a hot taste j alcohol and pyroxylic 

 spirit dissolve a much larger quantity. Sulphuric acid dissolves it in 

 large quantity, but it separates when diluted with water. 



Muriatic acid in its nascent state acts upon pyroxylic spirit and 

 produces chlorhydrate of methylene. The best process for obtaining 

 it is to heat a mixture of two parts of common salt, three of sulphuric 



* In the Ann. de Chim. cl de Phys., this is by mistake printed 2 atoms. 



