L ANIMALCULA OF INFUSIONS. 6% 



manner as Infufion animalcula and infeds can 

 refill cold lefs than their germs, fo do they lefs 

 refill heat. A caufe for the difference has alfq 

 been attempted to be aifigned, and what has been 

 faid v/ill apply to the prefent cafe, which the 

 reader may fee by refuming the pafl'age. There 

 is dill a more obvious caufe : inleds killed at 

 16*^ and 14° are fo penetrated and frozen by 

 the cold, that their members do not yield to the 

 preflure of the finger, and feem perfeft ice under 

 the knife. This does not happen to eggs, though 

 fubjefted to a much greater intenfity. Their 

 humours remain fluid, even at the greateft cold, 

 as may be feen by crufhing them with the nail. 

 Perhaps this is derived from conilituent fpirituous 

 or oleaginous parts, or from fome priA.ciple 

 adapted to abate the power of cold ( i ). If eggs 

 do not freeze, it is probable the included em- 

 bryos do not freeze. Is there any thing won- 

 derful, therefore, that they then furvive cold 

 which is fatal to them when produced ? Pro- 

 bably for the fame reafon, (and I fee no objec- 

 tion 

 (i) To underftand this in its full extent would be er- 

 roneous ; for an egg will freeze by a great degree of cold : 

 at the fame time, there feems to be a living principle 

 which enables it to fupport cold without deftruftion ; and 

 when once that principle is deftroyed, cold more eafily 

 operates. An egg was froze by die cold of o ; after thaw- 

 ing, it froze feven minutes and a half fooner. A new laid 

 egg took half an hour to freeze in 15'' and 17° ; but when 

 thawed, it froze at 25^* in half the time. Hunter on the 

 Anirial O?cono7?iy>—1!!^ 



