( 6y6 ) 
was always fomething wanting to render the Succefs of 
the Operation certain. The whole Secret then of 
Blanching lies entirely in the Preparation of this Suet : 
And this he at laft difcovered to confift only in firft 
frying and burning it- which not only gives it the Co- 
lour, but puts it into a Condition to give the Iron a 
Difpofition to be tinned, which it does furprifingly* 
TheTin itfelf ought to have a certain Degree of Heat- 
for if it is not hot enough it will not ftick to the Iron- 
if it is too hot, it will cover it with too thin a Coat, and 
the Plates will have feveral Colours, as a Mixture of 
red, blue, and yellow, and the whole appear of a villain- 
ous yellow Caft. To prevent this, by knowing when 
the Tin has a proper Degree of Heat, they might firft 
make an Effay with fmall Pieces of the fcaled Plates, and 
they would learn from them when the Tin is in proper 
Order: But generally fpeaking, thev dip the Plates in- 
to Tin that is more or lefs hot, according to the Thick- 
nefs they would have the Coat to be of. Some Plates 
they only give one Layer to, and thefe they plunge in. 
to Tin, that has a lelfer Degree of Heat than that in- 
to which they plunge thofe Plates which they would 
have take two Layers ; as alfo when they give thefe 
the fecond Layer, they put them into Tin that has not 
fo great a Degree of Hear, as that into which they were 
put the firft Time : Befides which, it is to be obferved 
that the Tin, which is to give the fecond Coat, ought 
ro be frefh covered with Suet, but only with the common 
Sort without Preparation ^ for melted Tin is fufftci- 
ently difpofed to attach it felf to folid Tin ; and in 
this Cafe it is to tin itfelf, to which the new Tin is 
to be joined. As to the Choice of the Tin, the Man- 
ner of making it is as bright as poflible, with a Num- 
ber 
