36 
able part of their composition; and that this air differs in no 
respect from the choke- or fire damp. 
This experimental enquiry was considered by the Royal Society 
of so singular and important a nature, that to the ingenious author 
of it, as the best publication of the year, Sir Godfrey Copley’s 
honorary medal was adjudged. 
In the year 1748, Dr. Brownrigg published his valuable work 
entitled, ‘The Art of Making Common Salt, as now practised in 
most parts of the world; with several Improvements in that Art 
for the use of the British Dominions.” He was prompted to 
undertake this arduous task from a general desire which at that 
period prevailed in the nation to promote and extend the British 
fisheries, and, by this measure, to find profitable employment not 
only for great numbers of seamen who, on the restoration of peace, 
had been discharged from the service of their country, but also for 
the natives of the north of Scotland. 
Dr. Campbell in his political survey of Great Britain, noticing 
Dr. Brownrigg’s treatise upon Salt, calls it “ta very learned, 
ingenious, and solid performance, than which,” he adds, ‘there 
is not perhaps anything more concise or more correct in any 
language.” 
This work was so highly approved by the Royal Society, that 
they conferred upon Dr. Brownrigg the singular honour of directing 
an abridgment of it to be made by Mr. William Watson, a worthy 
member of that learned Society, which they published in Vol. 46 
of their Transactions. 
The metal Platina di pinto, juan blanco, or white gold, was the 
next object of Dr. Brownrigg’s attention. The first specimens of 
this article having been originally carried from Carthagena, in 
New Spain, to Jamaica, were brought to England in 1741 by 
Mr. Charles Wood, and were given by him to his relative Dr. 
Brownrigg, who presented them to the Royal Society in 1750, 
accompanied with an accurate and ingenious account of its origin 
and properties, which was inserted in Vol. 46 of their Philosophical 
Transactions, under the title of “Several Papers concerning a New 
Semi-metal, called Platina.” Platina has been improperly styled 
