v CADDIS-WORMS 237 



Metiers, published by the Academy with the help of 

 the French Government. It led Reaumur to make 

 a long series of discoveries of much practical and 

 scientific interest. We find him investio-atinsf the 



o o 



tension of cords, and proving that, contrary to the 

 belief of practical men, they are weakened by torsion 

 (twisting). He experimented on the ductility of 

 metals, the lustre of pearls and fishes, the growth of 

 shells, the colour of the turquoise, the crystalline form 

 of certain metals and the manufacture of steel, which he 

 is said to have introduced into France. Tinplate too, 

 which had always been imported from Germany, was 

 first made in France according to the method taught 

 by Reaumur. He endeavoured to reproduce the 

 porcelain of the Chinese, but failed to get the desired 

 product, though he discovered the kind of white 

 glass still known as Reaumur's porcelain. He brought 

 into practical use the ancient method of hatching 

 eggs by artificial heat, showed how to preserve eggs 

 from putrefaction by greasing the shell, and sug- 

 gested improvements in the hanging of carriages and 

 the fitting of axles. Among his countless researches 

 are treatises on the production of spiders' silk for 

 commercial purposes, on the purple of the ancients, 

 on the sealing of tubes by mercury, on gold in the 

 rivers of France, on the Torpedo and its electrical 

 organ, on the fossil shells of Touraine, and on the 

 phosphorescence of shells. 



The thermometer by which Reaumur is best known 

 to the public was constructed on an original plan. 

 He divided the liquid contained in the bulb and the 

 tube up to the freezing point of water into a thousand 



