C LI MATE' of RUSSIA. 243 



SIR, . January 23. 1789. 



An idea has (truck me fince I fent off my lad letter, which 

 may pombly merit your attention, and therefore I fhall give it 

 you. 



Both of us know long ago, Sir, and we have probably felt 

 it lately, that when a fevere froft has lafted for a certain time 

 without intermiflion, we may in vain ftrive to prevent feeling 

 its effects on our own bodies, as well as our furniture, although 

 we even remain within doors in a comfortable fpring heat, with- 

 out expofing ourfelves to the open air at all. It might be fup- 

 pofed that thefe precautions would be fufficient ; but they are 

 in fact far from being fo : for as foon as the fevere cold has 

 lafted fome time, we find ourfelves attacked with a difagreeable 

 fenfation, which, like all the reft of our fenfations, there is no 

 defcribing exactly. I fliall therefore only fay, that it confifts in 

 a fort of laffitude and heavinefs or torpor, affecting both the 

 body and mind, joined to a troublefome reftleffnefs or inquie- 

 tude. Such are our feelings during the continuance of the 

 above defcribed weather, and I fhall next give you, Sir, my 

 conjectures on the caufe of this curious phenomenon. 



In the letter I had the honour to write you fome weeks ago, 

 I proved, that great cold renders the air dry and pure in a moft 

 aftonifhing degree, and that the heat which it afterwards re- 

 ceives in our apartments, renders it drying in a proportion 

 equally furprifing. Now, is it not poflible that it is this fame 

 drying quality of our chamber-atmofphere which produces the 

 fenfations enumerated above ? For why mould it not attack, un- 

 der the fame circumftances, the human body, as well as our 

 wooden furniture, and all other bodies which happen to be in 

 the rooms ? Surely, what we call perfpiration muft be much 

 increafed by it ; and this confumption of our excreted fluids 

 may pofhbly be extended, I fhould think, to the nobler fluids 



neceffary 



