118 Brass. 
himself were only illusory, and his expectations have not - 
been confirmed by time. 
The second paragraph contains an account of a paper 
on tinning, presented to the same academy by J. B. Ke~ 
merlin in 1742. One may see there the examination of 
it by Messrs. Hellot and Geoffrey, who entertained an 
opinion contrary to the assertions of the author. 
The same year the academy charged Hellot and Geof- 
froy to examine the alloys of zinc proper for making ves- 
sels. The inconveniences pointed out by the two acade- 
micians, as well as by many others, were verified by 
Proust ; and all of them are inclined to proscribe such 
alloys. Having made a mixture of equal parts of lead and 
zinc, similar to that examined by the two commissioners, 
he obtained an alloy of a paste-like consistence, as easy to 
be cut with a knife as cheese, and difficult to be cast. M. 
Pierre Blanco, a very ingenious pewterer, seconded the 
labours of Proust. The first time he poured the alloy 
into the mould, it did not run sufficiently to fill it. He 
tried it a second time ; and, when he thought he could 
draw it from the mould, it fell into pieces, as they had no 
cohesion. Being desirous to procure a piece well or ill 
moulded, he found himself obliged, at the third time, to 
cool his mould in cold water, and to employ double the 
time necessary to cast a piece of the same size with com- 
mon alloys : the vessel obtained broke short, and was fill- 
ed with defects which could not be remedied. A pound 
of alloy was employed, and the article weighed only nine 
ounces. The whole of the residuum was mere loss. 
The same article acquired in a month a dark colour, 
and at the end of six months was covered with oxyd ; 
inconveniences which do not take place in vessels of 
common tin. The author still continues to make seve- 
ral practical objections, to which no one has given an an- 
swer. 
