6y Mr. Hatchett’s Analysis of 
an additional portion of oxygen, by being treated with nitric 
acid; also that several of these alternate operations were required, 
before any given quantity of the metallic oxide could be com- 
pletely combined with the alkali. Now there is much reason to 
believe, that in this case, when the metallic oxide or acid was 
digested with potash, the portion which was dissolved, received 
an accession of oxygen at the expense of the other part, which 
of course was thus reduced to the state of an insoluble oxide, 
and therefore required to be again oxidated by nitric acid, 
before it could combine with the alkaline solution ; but still it 
appeared, that an adequate proportion of oxygen could never 
be superinduced, so as to render the oxide totally and imme- 
diately soluble in the alkalis by one operation, or even by two. 
We may, therefore, regard this as an instance of the effects 
resulting from disposing affinity, and as very similar to those 
observed in respect to copper, which have been noticed by my 
ingenious friend Mr. Chenevix, in his valuable analysis of the 
arseniates of copper and of iron.* 
My researches into the properties of this metal, have of course 
been much limited by the smallness of the quantity which I had 
to operate upon ; but I flatter myself that more of the ore may 
soon be procured from the Massachuset mines, particularly as 
a gentleman now in England, (Mr. Smith, Secretary to the 
American Philosophical Society,) has obligingly offered his as- 
sistance on this occasion. We shall then be able more fully to 
investigate the nature of this substance ; and shall be more 
capable of judging how far it may be applicable to useful pur- 
poses. At present, all that can be said is, that the olive green 
prussiate and the orange-coloured gallate are fine colours; 
* Phil. Trans, for 1801, p/233. 
