76 



On the Density of Solid Mercury. 



[Mar. 15, 



to acquire the temperature of the balance-case, and weighed. Three such 

 experiments gave, aside from the weight of the flask itself, 



grms. 



A. Mercury + alcohol at -39° C. =576-2029 



B. „ „ „ -41°-5 =576-2522 



C. „ „ „ -42° =576-2639 



Deducting the mercury, the quantity of which remained constant 

 throughout, it appears that the flask contained of alcohol : — 



grms. 



A. at -39° 17-2676 



B. „ -41°-5 17-3169 



C. „ -42° . 17-3286 



From the data in (10) these weights represented at the respective 

 temperatures the following volumes : — 



cub. centims. 



A 20-2865 



B 20-3061 



C 20-3122 



From the data in (4) and (5) we get the capacity of the flask up to 

 the mark at the same temperatures : — 



cub. centims. 



At -39° 59-6609 



„ -41°-5 59-6568 



„ -42° 59-6560 



Subtracting the volume of alcohol in each case, that of mercury was, 



cub. centims. 



In A 39-3744 



„ B 39-3507 



„ C 39-3438 



Hence the specific gravity as obtained 



In A 14*1954 at - 39° 



„ B ...... 14-2034 „ - 41°'5 



„ 14-2064 „ - 42° 



(12) By comparing these numbers in pairs, we have as the difference 

 apparently due to a difference of temperature of 1° C* :— 



From A and B -0032 



„ BandC -0060 



„ AandC -0037 



of which the mean is -0043. 



Eeducing, by using this coefficient, the above results to a single tem- 



* Of course really including errors in determination of weights and temperatures. 



