On the Density of frozen Mercury. 323 



balance, in the same alcoholj and at the same temperature, 

 lost 88-JOo grains of their weight. Upon this, Mi. Bicltilc, 

 rcirardinir the los? of weight of the mercurv and silver as in 

 an inverse ratio to the specific weiglits of these metallic sub- 

 stances, and having found that that of silver, with the same 

 balance and in distilled water, was 10-43G, lie multiplied 

 this sum by 86-105, and divided the product by 59"8, which 

 gave him 13-C12 for the specific weight of the mercury in 

 a solid state. 



But the same hydrostatic balance having given the num- 

 ber 1. 3-545 for the specific gravity of the same mercury in 

 the liquid state, the thermometer being at + 47° Fahr. ( + 

 61° Reau.), it would seem that nothing remains but to con- 

 clude with the author, *' that the volume of solid incrcury 

 is less by about one-seventh of what it is in the liquid slate." 



But arc all the principles of these calculations faultless ? 

 Are none of these wciglus evidently wrong ? I shall not 

 make a gratuitous supposition ; I shall judge by facts alone. 



The antiont tables of specific gravities give 0-806 for that 

 of alcohol or rectified spirit of wine. It is at abotit 0-820, 

 in the temperature of 19° of Reaumur (+ 3 }.V° Fahr.), ac- 

 cording to M. Bories, of Marseilles, at which the operations 

 on these substances can be regarded as decisive authority. 

 \Vc then fairly value it 0-SlO, without encroaching much 

 upon truth. But tlie liquid mercury, which, according to 

 its specific gravity of 13-545, loses in distilled water 73-828 

 grains in the thousand, ouo;ht to lose 59-8 in alcohol at the 

 wein-ht of 0-910 ; and in this manner the great difference 

 disappears which Mr. Biddle thouglit himself entitled to 

 mark bet'v\ cen the density of liquid and solid mercury. 



Pure silver, which in consequence of a specific gravity of 

 10-43G ouL'^hl to lose in distilled water 95-822 grains in the 

 .1000, would lose no more than 77-615 in alcohol at 0-810, 

 which is very different from 88-105. To account for this 

 diflcreticc, we cannot allege the greater density of the al- 

 cohol at tlie temperature of — 4 7° Fahr., because ihat could 

 not contribute more than two or three grains at must to the 

 loiss of the weight of tlie silver : we should not be bet'er 

 fdiuidi.d in supposing that the alcuboj eiT)ploycd happening 

 X 2 to 



