Brass . 
117 
if you wish to have the surface perfectly smooth and even, 
you may apply a thin coating of tin, which will fill up all 
the cavities and render it quite even, A coal fire is the 
best for this tinning ; for turf coals attack the metal, and 
interrupt the union and fusion of the coating. 
[7 Tillochy 218. 
JEx tract from a work , published by Professor Proust, en- 
titled Researches on the Tinning of Copper , on Tin 
Vessels , and glazed Pottery ; published at Madrid \ 
1803. 
THE author, in the introduction, says, that the motives 
which induced him to undertake this labour were the 
doubts spread abroad, two years before, among the pub- 
lic in regard to the salubrity of tinned copper, and the ac- 
counts of the disagreeable accidents arising from vessels 
'badly glazed. Government, always attentive to every 
thing that can tend to calm the public mind, had recourse 
on this subject to sound chemistry ; the only tribunal 
competent to banish doubts of this kind. Two pro- 
blems were presented to the author to be resolved : 
1st, Is the use of zinc advantageous cr not, for tinning 
and for tin vessels ? 
2d, Can tinning, in consequence of the lead it con- 
tains, and sometimes in large quantities, expose the health 
of the public to the same dangers as glazing of a bad 
quality ? 
The author divides his work into three chapters, and 
each chapter into several paragraphs. 
The first part, which may be considered as historical, 
is divided into four paragraphs. 
In the first the author mentions the project which was 
presented by M. Malouia to the Academy of Sciences at 
Paris in 1741, in regard to the employment of zinc for 
tinning iron and copper ; the advantages he promised 
