OKA, DENSITY OF SOLID MERCURY. 



that the whole became attached to the inner furface of the 

 glafs, and could not be feparated until the glafs with its con- 

 tents was taken out of the freezing-mixture, and warmed, by 

 dipping it in water, fo as to (often the mercury at the furface 

 attached to the glafs; one hand being applied to the wire at 

 the fame time, to draw the mercury from the glafs at the 

 moment of its being loofened : it was then replaced, as be- 

 fore, in the freezing-mixture. 

 Viflble figns of During the congelation of the mercury it was obferved, 

 great contraction the f ur f ace f t h e metal towards the centre was very confi- 



of the mercury . ... 



by freezing. derably deprefled by the contraction of its particles, and the 



veffel having been moved during its congelation, a fmall hole 

 nearly reaching the bottom of the glafs, was obferved gra- 

 dually leffening in its dimenfions, prefenting a conical cavity 

 with the apex downwards. The wire which held the mercury 

 attached to it was now fixed by the other bent end to the 

 hydroftatic balance, which held in the oppofite fcale the 

 weights by which the mercury had been weighed in the ajr, 

 together with the balance of the wire immerfed in the fame 

 alcohol to a point marked on the wire. 

 Lofsofweignt It appeared by weighing the 1000 grains of mercury thus 



by the immer- j mme rfed in alcohol, the lofs of weight was 59,8 grains : this 

 was weighed five or fix times, with the glafs Hill in the freez- 

 ing mixture, with the fame refult; but when it was with- 

 drawn only a little way from the muriate of lime and fnow, 

 the difference of weight was perceptible, in confequence of 

 the temperature of the mercury and alcohol increafing. 

 Comparative ex- One thoufand grains of pure filver, weighed by the fame 

 perimentwith an f ca | e immerfed in the fame alcohol at the fame temperature, 

 equal weight or. .,"'». . ir i i r r , 



filver. loft in weight 88,10.5 grains: therefore, as the lofs of the 



weight of the mercury is to the lofs of weight in the filver, fo 



is the fpecific gravity of the filver to the fpecific gravity of the 



mercury. 



Whence the fpe- The fpecific gravity of the filver in the fame balance having 



ci fie gravity of been afcertained, by diftilled water, to be 10,436, it follows, 



deduced tf tn ' s ^ um ^ e multiplied into the fum of its lofs fufpended and 



— 15.612- weighed in alcohol, and divided by the fum of lofs of mer« 



cury weighed in the fame way, that the fpecific gravity of 



the mercury in the folid ftate, at about 40 degrees below zero 



on Fahrenheit's fcale, equals 15,612. 



By 



