Jo me chemical Experiments on Tabafheer. 379 
Some of this clear liquor, mixed with marine acid, effer- 
vefced; did not afford any precipitate; but, on {landing feme 
days, the mixture became (lightly gelatinous. 
(G) Some of the thick jelly remaining otv the filter, being 
boiled in water and in marine acid, appeared infoluble in both, 
and feemed to agree entirely with the above powder (F). 
With dry alkalies . 
§ XII. (A) Tabafheer melted on the charcoal at the blow- 
pipe with foda, with confiderable effervefcence. When the pro- 
portion of alkali was large, the Tabalheer quickly difl'olved, and 
the whole fpread on the coal, foaked into it, and vamihed ; 
but, by adding the alkali to the bit of Tabafheer in ex- 
ceedingly (mall quantities at a time, this fubftance was con- 
verted into a pearl of clear colourlefs glais, 
(B) 5 gr. of Tabafheer, reduced to fine powder, were melted 
in a platina crucible with 200 gr. of cryftals of foda. The 
mafs obtained was white and opaque, and weighed 40.2 gr. 
Put into an ounce of diftilled water, it wholly diffolved. An 
excefs of marine acid let fall into this folution produced an 
effervefcence, and changed it into a jelly. This mixture was 
ftirred about, and then thrown upon a filter. The jelly left on 
the paper did not diffolve in marine acid by ebullition ; col- 
letted, wafihed with diftilled water, and dried, it weighed 4.5 
gr. and feemed to be the Tabafheer unaltered. 
The liquor which had come through being fatu rated with 
mineral alkali yielded only a very fmall quantity of a red pre- 
cipitate, which was the colouring matter of the pink blotting 
paper through which it had been paffed. 
D d d 2 
(C) 10 
