SIR B. C. BRODIE ON THE CALCULUS OF CHEMICAL OPERATIONS. 845 



where x and y have the values previously assigned to them (Sec. VII. Grroup 2 (1)), and 

 assuming x=\, 



y\ y 



whence, putting y^ as the number of volumes of zinc formed, a"*'"'^"'' as the sj-mbol of 



zinc-ethyl, a"*"'^"' as the symbol of zinc, a as the symbol of hydrogen, and «* as the 



symbol of carbon, 



yyiioTxr^r;^) = byy^a + ^^x^+yy^aTK^^ 

 and 



whence 



y^m =^yi-\-yin, 



yiWi=4yi+y3«i> 



which equations have for all integral values of y^ and y^ the minimum solutions, 



m =5, ri=0, 



which give the following expressions for the symbols, 



Zinc-ethyl . . . a'K%»\ 

 Zinc X^\ 



In a similar manner we arrive at o^k^'Q^ as the symbol of zinc-methyl. 



These are the only gaseous compounds of zinc known. 



The specific heat of zinc is 00955. Hence it may be assumed that 



. _3;289 _ 

 -'^ - 0-0955 -^*'*' 



Now from the above equtions 



?^W=32-75, 

 W being the density of zinc in the gaseous condition, and approximately 



(1) If A=W, 5^3=1, andy,=:l. 



(2) If A=^.y3=l, andyi=2, 



W 



(3) If A= -r ' yy=X and yi=4. 



MDCCCLXVI. 6 T 



