Pm 
Kwperiments on Anthracite, Phunbago, &. 107 
— experiments were mad: with Plumbago from 
several other localities; the results of which were no wise 
teem and therefore need no further mention. 
Experiment 6th. A piece of charred mahogany, during 
its combustion by the compound blowpipe, presented numer- 
ous small, imperfect globules, owing to the foree of the flame, 
which dissipated their support before they had time to form 
or to accumulate to any considerable size; many of them 
adhered tog ther, ramifying like flos ferri, which they resem- 
bied; they were collected by placing a dish under their sup- 
port. ws ‘the Pra a flux, they readily fused into a 
ble to the naked eye or to the microscope. The heat was 
equally as intense in this experiment as in all the other in- 
stances, and no condition was wanting to produce the same 
effects, except the difference of composition. After burning 
the lampblack for as long a time as was thought necessary to 
make the experiment a fair one, it was again weighed, and 
found to en lost four grammes, ;43,, for it weighed but twe 
grammes, 
Five <oqweinines of the same lampblack vio in an open 
platina erucible, Jeft after its incineration, o ntigramme 
of white ashes, equal to ;4, of the mass. 
rom the analyses of the substances, used by Professor 
Silliman, from which the globules were oo” it appears 
that they all contain foreign matter, as silex, iron, manganese, 
and some of them also alumine; that when Tampblaeke was 
used which contained but =25 of fixed ae ot no distinct 
globule or melted matter was formed ; although the heat was 
sufficiently great, and the combustion slow enough to admit 
of the forming of globules, if their production was owing to 
the fusion of carbon, and not to extraneous matter. From my 
own experiments I always found that the more impure the 
‘substance was, the more numerous and the larger were the 
globules produced. 
All the globules from the different kinds of substances4ssed, 
were réadily fused by the compound flux, and yuderwent 
