2y> Olfervationi an the Freezing of Water , 



At prefent, bowjver, I fliail give you only a lliort. account 

 of m- experiments, becaufe I hope, in ihe courle of a few 

 years, lo colleA materials for a more elaborate work on the 

 freezing of water, and the Itate of the atmofphere in winter; 

 having bten induced lo turn my attention to the latter objeft 

 by the obiervalions 1 had Hiade, and which I mentioned to 

 voii three veari jto, on the lorce with which a conliderable 

 quantity of vapour, efpecially during the time of ftrong froft, 

 is difengaged in an aeriform ftate from freezing water, and 

 rifes, as it were, with violence into the alniofphere ; and on 

 the increafe of V(/uime which the air thereby acijuires even 

 in clnfe vefielsj and which it retains during the ftrongefi; cold. 



When I ifoLverfe the fnow-clad fields during the coldeib 

 days of winter; when I conlidcr the drv ibte of the air, and 

 of every thing aroimd me, arifing, no doubt, from a flrong 

 and centinued tendency of the aqueous particles, of which I 

 neither fee nor feel' any thing, to rife into the higher regions 

 of the atmofphere; and when in confequence of the fcrenily 

 of the heavens I can didinguifli very fmall objecls at a great 

 diftance, I cannot help admiring the power of nature, as yet 

 fo little known, by which air fo cold and fo much condenfed 

 can be fo intimately conneoled with water. This water, in 

 my opinion, can be confideicd only as in an aeriform flate, 

 as fuch combined with the atmofphcre by a very Itrong affi- 

 nity, aixd forming .with it one and the fame body : I mud 

 obfcrve alfo, thai this affinity fccms to increafe in the ratio 

 of the cold. , 



The atmofphere being, an claftic fluid in which caloric i* 

 combined by the Hrongeii affinitv with its bafes, it by thefe 

 means appears to be more capable of pfeierving by the power 

 of this union, in the (fate of almofpheric vapour, the aeriform 

 water which has fo weyk an affinity for its fpecilic caloric. 

 The air thus condenfed, and containing more aerial particles 

 in the fame fpace than in fummcr, attrafts, on this account, 

 the water with much greater force. The water becominf 

 aeriform during the procefs of frCezingj and' in that (late en- 

 tering into combination with the air, has no need of external 

 heat to maintain it in that date of union. The aeriform 'date 

 f>f water, which in fummer is maintained by the heat of the 

 furrounding bodies, is in this feafon preferred by a date of 

 greater affinity. 



Js the water tBen, during this cold, fercne, winterv atmo- 

 fphere, in a nrore perfeft date of union with the air? I an- 

 fwer rn the alErmative ; and therefore I can readilv conceive 

 whv tb.e mercury (lands at Inch heights in the barometer 

 during that ledbn. This air alfo may be confidered as a re- 

 ceptacle 



