CLIMATE of RUSSIA. 227 



Theory of Latent Heat ? For as water requires a great portion 

 of fenfible heat to refume its fluid form, of courfe, a large 

 proportion of that furnifhed by- the fun will be abforbed, un- 

 til the whole is dilfolved, when we at once receive all his influ- 

 ence, without any part of it being abforbed by our winter co- 

 vering. When this caufe is joined to the cold produced by the 

 evaporation going on during the thawing period, it is eafy to 

 conceive how different our feelings muft be at the time when 

 they are both removed, and the earth is beginning to ac- 

 quire and give out warmth ; which very quickly takes place in 

 this light fandy foil, that lets the water readily filter through it, 

 and almoft immediately begins to heat. 



RUSSIAN SUMMER, 

 With the common Pheiiomena attending it. 



Our Ruflian fummer, during a good feafon, prefents exadtly 

 the oppofite extreme to winter, the former being nearly as hot 

 as the latter is cold ; an admirable arrangement of nature, if 

 we confider the taflc the fun has to perform, with regard to ve- 

 getation, during that fhort fpace of time. The influence of 

 the fun dm^ing the period of a Ruflian fummer, is no doubt 

 aided by that equally wife ceconomy relative to the habits of 

 plants ; for whilfl: the northern ones run their courfe uniformly 

 in the fliort fpace of time allotted to them, (even in Iceland, 

 where, from its infular fituation, the heat cannot be fo confi- 

 derable as with us), thofe imported from the fouth can, by no 

 means, effecSt all their fl:ages of vegetation, within the bounds- 

 of a Ruflian fummer, until they have pafled a few feafons in 

 this climate, and thus acquired the habits of the indigenous 

 plants of the country. 



It is remarkable, that the thermometer falls exadly to 24° i- 

 of Reaumur below the freezing point, during our greatefl: 



// 2 cold 



