Biographical Memoir of Count C. L. BerthoJlet. 3 
year 1786. Some of bis experiments, of which he made no se- 
cret*, were exhibited to our late distinguished countryman Mr 
Watt, who immediately saw the importance of the discovery, 
and some time afterwards actually applied 5 it in whitening 500 
pieces of cloth. In the beginning of the year 1788, some fo- 
reigners attempted to obtain in England a monopoly of this va- 
luable process, but their application for a patent was resisted by 
Mr Watt, and by Mr Cooper, and the late Mr Henry of Man- 
chester; and the two last of these gentlemen formed the first 
establishments in which this great discovery was first applied on 
a large scale. The great improvements in this process, which 
were subsequently made by our countryman Mr Tennant of 
Glasgow, in combining the oxymuriatic acid with lime, and in 
forming a portable bleaching salt, by uniting the gas with dry 
quicklime, have increased the value, and widely extended the 
utility of Berthollet’s discovery. 
The combinations of the oxymuriatic acid with the alkalies, 
though equally interesting in a scientific point of view, have not 
yet found the same useful applications. The experiments of 
Berthollet on the oxide of ammoniacal gold, made us better 
acquainted with this dreadful compound, though its effects are 
still less frightful than those of the fulminating silver, which he 
discovered soon after, and which explodes violently, even by the 
percussion occasioned by a drop of water falling upon it. 
In the examination of these compounds, our author seems to 
have been led to those experiments, by which he has conferred 
on the art of dyeing as great a benefit as that which he rendered 
to the kindred art of bleaching. Hitherto that branch of the 
useful arts consisted of the most absurd receipts, and was found- 
ed upon the most ridiculous theories. Hellot, Macqueer, Ban- 
croft and Bergman had indeed begun to renovate the art of 
dyeing. Mr Keir and Mr Bancroft appear to have been the 
first who suggested the true theory of mordants ; but it is to 
Berthollet undoubtedly that the complete establishment of the 
theory belongs. 
* The only advantage which Berthollet derived from this great discovery, was 
a present of a bale of cotton-stuffs bleached by his process, which was sent to him 
by an English manufacturer. This fact is stated by M. Auger. It is probable 
that they were sent by Mr Watt. 
