Experiments on freezing Mixtures . 269 
the remainder is no longer fmoking, and has loft its glacial 
quality 
On the Mixture of Oil of Vitriol and Spirit of Nitre . 
29. This mixture is not fo fit for producing cold by the ad- 
dition of fnow, as oil of vitriol alone; for the cold obtained 
did not exceed — 54°!, in either of the experiments tried with 
it. The point of fpirituous congelation of this mixture, when 
diluted with fomewhat more than one -tenth of its weight of 
water, is about - 20°, and is much lower when the acid is con- 
fiderably more diluted : but as the Society will moil likely have 
lefs curiofity about the difpofition to freeze of this mixture 
than of the fimple acids, I fhall fpare the particulars. 
On the Spirit of Wine « 
30. The re&ified fpirits N° 8. were diluted with fnow, in 
the fame manner as the other liquors ; but were found not to 
want any, as the firft and only addition of fnow produced 
cold. The quantity added was about of the weight of the 
fpirit. 
31. The fpirit thus diluted was divided, like the other 
liquors, into two parts, and each tried feparately. The 
firft was at -45% before the addition of the fno^, and was 
funk by the procefs to — 56°. The fnow, even at the firft ad- 
dition, did not diffolve well, fo that the fpirit immediately 
* Crell’s Neil. Entdeck. in der Chemie, Th. ii # p» 100. Th. 12. p. 241, 
&c. and Annalen, 1785, St. 5. p. 438, &c. 
3 became 
