Physics and Chemistry. 419 
in pale yellow micaceous scales insoluble in all reagents. Dried 
even at ordinary temperatures it agglomerates to brown amorphous 
tenacious plates in which the primitive structure has disappeared, 
This character is essential and invariably reappears after all the 
transformations of the oxyd. TIodhydric acid at 280° C. converts 
graphitic oxyd dis sin a mixture of nitric acid and potassic 
chlorate in a much more complete manner than that from plumba- 
gine. Some scales of the original gr: c oxyd are however 
always formed with their distinctive properties. 
raphitic oxyd from electric graphite—carbon points from a 
large battery—is a maroon colored powder which does not ag- 
raphitic oxyd with its original properties, mes 
the pyrographitic oxyds when treated with iodhydric acid in 
solution at 280° C. yield hydrogen containing about 6 per cent of 
gas, leaving however a considerable quantity of a black 
and ulmic matters, and believes that the varieties of amorphous 
lymeric states of the true carbon which is not 
en or uncondensed form. In studying the 
celain tube, is dissolved with very great difficulty but completely. 
The same is true for gas-retort carbon and some substances called 
