184 REAUMUR. 



The President Henault^ who held a distinguished 

 station among the literati of PariS;, and who was 

 his relative, introduced him to the scientific world. 

 In I7O8, when only twenty- four years of age, he 

 presented some geometrical memoirs to the Academy 

 of Sciences, who were so much pleased with his 

 performance as to admit him into their society, — an 

 honour which he enjoyed nearly fifty years. His 

 exertions were directed successively to the improve- 

 ment of the arts, to natural philosophy,, and to na- 

 tural history. From his entrance into the academy 

 he scarcely allowed a year to pass without publish- 

 ing some work of importance. Soon after his ad- 

 mission he was appointed to assist in drawing up a 

 description of certain arts and trades ; but not con- 

 fining himself to a simple elucidation, he endeavour- 

 ed also to improve them, by applying the princi- 

 ples of physics and chemistry. On the other hand, 

 by observing the ingenious combinations employed 

 in some of the arts, he had frequent opportunities 

 of adding to his knowledge of the phenomena of 

 nature. 



In his inquiries into the business of ropemaking, 

 for example, he proved by conclusive experiments 

 that, contrary to the common opinion, twisting im- 

 pairs the strength of ropes. Again, while describing the 

 labours of the goldbeater, he took occasion to show the 

 prodigious ductility possessed by certain substances. 

 But, more especially, when examining the processes 

 by which artificial pearls are coloured, he discovered 

 the singular matter which gives lustre to the scales 

 of fishes, and even explained the formation and growth 

 of those scales. The colouring principle in glass pearls 

 is obtained from thehleak{Ct/prmusalburnus)yan 



