/ 



86 Br. IIolyoke's Estimate of the Excess of Heat and Cold. 



for the greater degree of cold on the eastern confines of 

 Asia, than on the western of America. 



w 



Be this however as it maj, I flatter myself that, what is 

 here offered, may excite some persons of taste and leisure 

 for such inquiries, to attend to the subjects here treated^ and to 



* 



examine with freedom the theory here advanced : that so. 



if it shall be found agreeable to reason and 



exp 



may be illustrated and confirmed; or, if other 

 be confuted and exploded. 

 Salem, Scptcmher, 1788. 



Ex 



POSTCRIPT, 



To a Paper eniitled, An Estimate of the Excess of the greatest 

 Heat and ^greatest Cold of the American Atmosphere legond 

 the European, under the same Parallel of Latitude, &c, 

 SINCE the Academy did me the honour to read a paper I 

 presented them in November 1788, entitled, An Estimate 



the Heat and the Cold, d'c. I have had the plea- 

 sure of reading in ihQ Philosophical Transactions, Vol. Ixxvii. 

 Article xv. an account of some very curious experiments 

 made by our countryman Sir Benjamin Thompson, at 

 Manheim, in the Palatinate fn Germany;' by which it ap- 

 pears that eider-down, cotton wool, raw silk, &c. yield as 

 much and as pure dephlogisticated air, as the leaves of any 

 kmd o\ vegetables by the same process; that is, by .__,,.. ^ 

 them, when immersed in water, to the action of the' sun'l 

 rays: and therefore, that most probably, this pure air is 

 derived from the water in which they are thus imn.ersed, 

 and not from the substances, whetho. .. 



expo 



ire table 



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mineral, 



