48 



OK tAf £Vr HEAT. 



lion of v^'ater mighl be wafted during the procefj. If we allov^ 

 a half of all the lofs to be accounted for in thefe ways, there 

 remain fixteen grains of water which have been converted 

 into fleam. The latent heat of fleam was computed, by Mr. 

 Watt, to be equal to 9 VO® : But this fteam cannot be allowed 

 fo much heat as this ; and though it may be difficult to point 

 the quantity to be fairly granted, yet I Ihallexpeftto be with- 

 in bounds when I eftiraate it at one half of 940^, or 470°. In 

 this cafe we fay, 16 grains of water have been heated 470*; 

 fixteen grains of bifmulh would be heated by the fame quan- 

 tity of caloric, 11 190°. 4; and 1555 grains-}- 16 grains fup- 

 pofed to have gone off with the water, ir: 1571 grains of bif- 

 Latentheatof muth, would be heated 113*^.9. This quantity of heat, there-* 



-'/T^^i!.lf "^ ^^^^' ^"g^^ ^^ ^® ^^^^^ ^^ ^^® 446*^.55 already found, and 

 would amount, in all, to 560.45 latent heat of bifmuth. 



I am fenfible that there are feveral gratuitous fuppofi lions in 

 this laft part of the reafoning, and I do not therefore lay much 

 ftrefs on it, I endeavoured to confirm or refute the truth of 

 the indu6lion«, by making an experiment exaftly on the fame 

 principles, but where, by dexterity, I might prevent the for-* 

 mation of fteam wholly or in part. In one inftance I fucceeded 

 tolerably well, and then the latent heat, with every correc- 

 tion, amounted to nearly 600°. 



I repeated thefe experiments for determining the latent heat 

 of bifmuth many times, and the refult is exprelTed m the 

 following 



560^ degrees. 



Other experi- 

 ments with bif- 

 muth. 



TABLE: 



Tabulated. 



On 



