Intelligence and Miscellaneous Articles. 77 



of the vessel and becoming burnt. In order to convert the spongy 

 mass thus formed into good caoutchouc, nothing more is requisite 

 than to expose it to moderate pressure between the folds of a towel. 

 By this process the whole of the aloetic extract, and other vegetable 

 matters, which concrete into the substance of the balls and junks of 

 caoutchouc prepared in Assam and Java, and contaminate it, are en- 

 tirely separated, and an article nearly white and inodorous is obtain- 

 ed. Some of the calies of American caoutchouc exhale when cut 

 the foetor of rotten cheese ; a smell which adheres to the threads 

 made of it, after every process of purification. 



In the interior of many of the balls which come from both the 

 Brazils and East Indies, spots are frequently found of a viscid tarry- 

 looking matter, which, when exposed to the air, act in some manner 

 as a ferment, and decompose the whole mass into a soft substance, 

 which is good for nothing. Were the plan of boiling the fresh juice 

 along with its own bulk of water, or a little more, adopted, a much 

 more valuable article would be obtained, and with incomparably less 

 trouble and delay, than has hitherto been brought into the market. 



I find that neither of the above two samples of caoutchouc juice 

 affords any appearance of coagulum when mixed in any proportions 

 with alcohol of 0"825 specific gravity; and, therefore, I infer that 

 albumen is not a necessary constituent of the juice, as Mr. Faraday 

 inferred from his experiments published in the 21st vol. of the 

 Journal of the Royal Institution. 



The odour of Mr. Sievier's sample is slightly acescent, that of Mr. 

 Beale's, which is by far the richer and purer, has no disagreeable 

 smell whatever. The taste of the latter is at first bland and very 

 slight, but eventually very bitter, from the aloetic impression upon 

 the tongue. The taste of the former is bitter from the first, in con- 

 sequence of the great excess of aloes which it contains. When the 

 brown solution which remains in the capsule, after the caoutchouc 

 has been separated in a spongy state by ebullition from 100 grains 

 of the richer juice, is passed through a filter and evaporated, it leaves 

 4 grains of concrete aloes. 



Both of these emulsive juices mix readily with water, alcohol, and 

 pyroxylic spirit, though they do not become at all clearer ; they will 

 not mix with caoutchoucine (the distilled spirit of caoutchouc), or 

 with petroleum-naphtha, but remain at the bottom of these liquids 

 as distinct as mercury does from water. Soda caustic lye does not 

 dissolve the juice ; nitric acid (double aquafortis) converts it into a 

 red curdy magma. The filtered aloetic liquid is not affected by the 

 nitrates of baryta and silver : it affords with oxalate of ammonia 

 minute traces of lime. — London Journal of Arts, March, 1839. 



ON THE PRErAllATION OF FULMINIC ACID. BY M. FEHLING. 



Fulminic acid is one of those which have not hitherto been obtain- 

 ed in an isolated state. When separated from its co.iipounds by 

 a stronger acid, it decomposes rapidly, and its elements form new 

 products by uniting in different proportions. 



MM, Gay Lussac and Liebig have unsuccessfully endeavoured to 

 isolate this compound. The decomposition of fulminate of silver by 



