AN ACCOUNT 



EXPERIMENTS 



MADE 



TO DETERMINE THE QUANTITIES OF MOISTURE ABSORBED 

 FROM THE ATMOSPHERE BY VARIOUS SUBSTANCES. 



EING engaged in a course of experiments upon the 

 conducting powers of various bodies with respect 

 to heat, and particularly of such substances as are com- 

 monly made use of for cloathing, in ' order to see if 

 I could discover any relation between the conducting 

 powers of those substances and their power of absorbing 

 moisture from the atmosphere, I made the following ex- 

 periments. 



Having provided a quantity of each of the under- 

 mentioned substances, in a state of the most perfect 

 cleanness and purity, I exposed them, spread out upon 

 clean china plates, twenty-four hours in the dry air of a 

 very warm room (which had been heated every day for 

 several months by a German stove), the last six hours the 

 heat being kept up to 85° of Fahrenheit's thermometer; 

 after which I entered the room with a very accurate bal- 

 ance, and weighed equal quantities of these various sub- 

 stances, as expressed in the following table. 



This being done, and each substance being equally 

 spread out upon a very clean china plate, they were re- 

 moved into a very large uninhabited room upon the 

 second floor, where they were exposed 48 hours upon a 

 table placed in the middle of the room, the air of the 



