162 Prof. Vanuxem's Experiments 



with nitro-muriatic acid. By evaporating the liquor to dry- 

 ness, and adding acidulated water and filtering, the silex was 

 obtained. To the liquor from this operation ammonia in ex- 

 cess was added ; and by this agent, the iron, manganese, and 

 alumine contained in the liquor, were precipitated ; the latter 

 was separated from the two former by caustic potash. No 

 attempt was made to ascertain the relative proportions of iron 

 and manganese, this knowledge not being considered import- 

 ant. The presence of manganese was evidenced by the green 

 colour of the alkaline fusion ; and a rose-colour, when acid 

 was added to the liquor. No allowance was made for the dif- 

 ference in the degree of oxidation of the iron and manganese 

 in the substances used, and the products obtained, as the 

 amount was less than one per cent, where most abundant. 



The first experiments made with the globules were with 

 potash and with carbonate of soda, on silver and on platina 

 foil : witli these agents I could not produce much effect ; but 

 by using a small quantity of carbonate of lime, carbonate of 

 soda and borax, on platina foil, their fusion, whether they 

 were coloiu^ed or colourless, opaque or transparent, was ei- 

 fected in a few minutes. 



Experiment 1. — A piece of the purest anthracite of Lehigh, 

 subjected to the blowpipe, presented numerous small white 

 globules ; few were tinged with violet, and two or three were 

 blackish ; the globules did not readily unite with one another : 

 however, by long continued heat, some of the globules were 

 obtained of the size of the head of a small pin ; the greater 

 number of them were but feebly translucent, and could be 

 broken by a moderate force ; others, though few in number, 

 were transparent, hard, and not so brittle. The white globules 

 were not magnetic, except when dark spots were present ; the 

 blackish ones were magnetic, and like the whole of them could 

 be fi*actured by pressure. The surface of the mass whitened, 

 as observed in the ordinary combustion of this coal, and pre- 

 sented veins or layers of the matter of the white globules, 

 showing that the impurities of the coal were not regularly in- 

 termixed with its carbon, or, upon the supposition of its being 

 fused carbon, that its production was extremely irregular. 



With the flux before mentioned the different kinds of glo- 

 bules were melted without difficulty. By heating a centi- 

 gramme and a half of the globules in powder, for a long time, 

 with caustic potash, about 3-4tlis of a centigramme of silex 

 was obtained. It manifested itsulf by its gelatinous appearance 

 before the water was driven off. 



The 



