254 THE POPULAR SCIENCE MONTHLY. 



a man of science, has a curious appearance now, but was all in 

 place in Key's time. Rey, who had answered the other objections 

 by argument, had recourse this time to experiment. " If a fur- 

 nace is built in a wall separating two rooms, in such a way that 

 the vessel shall be on one side and the ventilating registers and 

 doors for feeding in coal on the other, I maintain that the increase 

 in weight will still take place, although no vapors can enter the 

 chamber containing the vessel. I have confirmed this by an ex- 

 periment which I made at the forges of Jean Rey, Lord of Perro- 

 tasse, my elder brother, where I found the increase in tin, which 

 I calcined on a pig, as they call it, or an ingot of sixteen or twenty 

 quintals of iron, at the instant when, coming out of the furnace, it 

 was cast into its mold ; for it can not be said that vapors of coal 

 contributed anything to it. Therefore, the volatile salt can not be 

 accepted in this case." 



Finally, with a single experiment Rey swept away all the ob- 

 jections in a lump. " I have just read in Homerus Poppius," he 

 said, " in the third chapter of his book entitled Basilica Antimonii, 

 of the new way that he practices in calcining antimony. He takes 

 a certain quantity of antimony, weighs it, and having pulverized 

 it, puts it in the shape of a cone on a marble ; then takes a burn- 

 ing mirror, holds it in the sun so as to bring the pyramidal point 

 of the reflected rays upon a point of the cone of antimony, whicn 

 fumes abundantly, and in a little while the antimony, touched by 

 the rays, is turned into a pure white earth, which he separates 

 with a knife and turns the rays upon the rest till all has been 

 turned white, and then the calcination is done. It is a wonderful 

 thing that, although in this calcination the antimony loses much 

 of its substance in the vapors and fumes that exhale from it 

 copiously, its weight increases instead of diminishing. Now, if 

 we ask the cause of this increase, will Cardan say that it is the 

 disappearance of the celestial heat ? That has been infused more 

 largely by means of the solar rays. Will Scaliger say that it is 

 by consumption of the airy parts ? Thinning into earth and increas- 

 ing in volume, it forces more in. Will Csesalpin allege his soot ? 

 There is no fire to produce any soot. Does the vessel give up any 

 of its own substance ? Indeed, the rays are conducted so directly 

 upon the matter that they do not touch the marble. Do you speak 

 of the vapors of charcoal ? No charcoal is used in this transac- 

 tion. The volatile salts which have been so ingeniously brought 

 forward lose here all their savor and grace. Perhaps moisture 

 will be suggested, as has been recently done by some one. But 

 where can it come from ? From the marble ? No, no, that is not 

 conceivable. From the air ? Still less ; for the operation is best 

 practiced in the warm days of summer, in the most violent heats 

 of the dog star." 



