Translation of Key's Essays. 283 



weight increases instead of diminishing. Now if we demand the 

 cause of this increase, will Cardon tell us it^is the disappearance 

 of the celestial heat? rather it is more largely infused, by means 

 of the solar rays. Will Scaliger say it is the consumption of 

 its aerial parts ? the particles of the calx being much attenuated 

 and its volume increased, it rather absorbs them more abun- 

 dantly. Will Csesalpine allege his soot as the cause? there is 

 no fire in this case to produce it. Can the vessel have con- 

 tributed any thing towards it ? the rays of the sun are so dex- 

 terously directed on the antimony, that they never touch the 

 marble. Will any one suggest the vapours of the charcoal? 

 none is employed. As to the volatile salts, that have been so 

 ingeniously brought forward, they entirely lose, in this case, 

 their savour and their grace. Peradventure moisture will be 

 adduced, as some one very lately has thought fit to do. 

 Whence comes it? From the marble? No, that is not conceiv- 

 able. From the air ? Still less so : for this operation is best per- 

 formed in the hottest days of summer — in the most violent heat 

 of the dog days, when every thing is so heated here below, that 

 even in the shade, or during the night, the air dries wet 

 linen, and the damp ground ; and in the day-time, where the 

 sun falls, it tans our skin, withers the grass, burns up the fruits, ~ 

 dries the woods, soaks up the lakes, lowers the streams of the 

 rivers, and inflames combustible substances, as a heap of 

 pigeons' dung. To look for humidity in the air to moisten our 

 calx and give it weight, at that season, not by night, but by 

 day, not in tlie shade but in the sunshine, not when the sun 

 simply shines, but when its rays, collected in a concave mirror, 

 are reflected with so much violence that they fuse and calcine 

 metals ; to look for moisture under such circumstances, I 

 say, is to seek fire in ice, and a knot in a bulrush, as 

 we say, a thing never to be found. Now let all the ablest 

 minds in the world be melted into one, and this fine spirit exert 

 itself to the very utmost of its strength, let it seek attentively 

 on the earth and in the heavens, let it rummage all the wind- 

 ings and turnings of nature, yet will it not find the cause of this 

 increase, but in the air alone, which heated, thickened and made 



