|7) ,.. ,.;. n. GRIFFITHS ANI> MR. EZER GRIFFITHS ON THE 



Messrs. Johnson and Matthey state : 



" Fully 99-75 per cent, pure, with very ' slight traces of iron and zinc.' ' 

 Series of four total heat experiments at C., with probable error of 0'08 per 

 M ,,t. gave S = 0-05468. TiBLE XXVI ._ Tin . 



Weight, 2591 grms. Density, 7 '292. 



S, = 0'05863 (1 + 0-0006704<-0'000000458 3 ). 



Messrs. Johnson and Matthey state : 



" Probably analyse to 99'80 per cent., with trifling quantities of arsenic, lead, 



and iron." 



TABLE XXVII Lead. 

 Weight, 4016 grms. Density, H'341. 



S, = G'030196 (1 + 0'000400<- 0-00000036^). 



Messrs. Johnson and Matthey state : 



" Approximate to 99'90 per cent., with inappreciable traces of arsenic and 

 bismuth." 



The "probable error" of the various groups with this metal is higher than in the 

 case of other metals. This is probably an effect of the low conductivity of lead and 

 the consequent steepness of the thermal gradient within the cylinder. 



Fig. 8 represents the increments in specific heat over the range C. to 100 C., on 

 the assumption that the specific heat at C. for each metal is represented by unity. 



We had hoped to present curves showing the actual values of the specific heat over 

 this range, but the scale required was so large, that we found that, if reduced to the 

 size necessary for reproduction, they were of little value. 



