ai low Temperatures , I S3 



At T, the Increased specific gravity of alcohol each degree 

 is '0004934. 



For the further variations of gravity see the annexed tdhle. 

 At K, a rule for finding the specific gravity of silver from 

 loss of weight at C^ and the specific gravity of alcohol att. 

 If silver at 50 above zero he 10'363, it will be 

 at 56 below zero 10*427. 

 At L, a rule is shown Ibr finding the specific gravity of mer- 

 cury .-—-At 200 above zero it is found lo be 12*407 



50 J3-613 



56 below »— 14'465 



The increase each degree is *00804 

 . A comparison of C and G as it relates to alcohol ; and by 

 the rule at I it appears they accord in the number '8665, 

 the specific gravity at 56 below zero. 

 At M, the contraction of mercury in its solid state, sup-^ 

 posed to be near twice that of silver, or '001 each degree, 

 because near the point of fluidity. 



Alcoholof the specific gravity *8854 at 76 below zero. 

 Mercury in a solid form of the specific gravity 14*485 

 at 76 below zero. 



The mode of calculating this is shown. 

 The increase of specific gravity of alcohol in each de- 

 gree not shown by the hydrostatic balance, when mercury 

 is weighed in it in a solid form, is '000061. 

 At N, rule for finding the increase of water of equal bulk 

 to that of mercury. It appears from F to be *0007^ each 

 degree. 



Rule for finding the ratio of contraction of mercury, 

 alcohol, water, and silver, of equal volume ; mercury being 

 supposed 100. 



A ratio of contraction also of water, mercury, alcohol, 

 ftnd silver; water being supposed 1*000. 



Rule also given to find the ratio of contraction of alco» 

 Jiol, water^ silver, and jnercury, of equal weight. 



XXIX, Essay 



