r CONTENTS. 



PAGI! 



XIX. Memoir on the Changes in the mean direction of the 

 Wind, in the Annual Period, in North America. 

 By M. Dove, 205 



XX. New Diluvian Formation of the Vosges, . 207 



On Artificial Quartz — Llamas and Alpacas in Holland — Diseases arising 

 during the manufacture of Brussels Lace. 



Paris Academy of Sciences. — Dec. 6. — M. Ebelmen submitted to the Academy 

 some specimens of artificial quartz. Amongst tliem are some to wliich he has 

 given various tints by mixing colouring substances with the silicic acid. The 

 specimens impregnated with chloruret of gold are remarkably beautiful. At 

 the end of a certain time the chloruret of gold is decomposed, and streaks of 

 gold appear in the entire mass. The decomposition is accelerated by the action 

 of the solar light, and under its influence also bright colours are obtained — 

 sometimes blue, sometimes red, and sometimes violet. By a modification of his 

 process, M. Ebelmen obtains a true natural mineral, the hydrophane. It is a 

 siliceous, porous, and opaque substance, which becomes perfectly diaphanous as 

 soon as it is plunged in water. M. Ebelmen has ascertained that this substance 

 absorbs gases as powerfully as charcoal. — A communication was received from 

 M. Christian Bonafoux, giving an account of the attempt made, by order of the 

 King of Holland, to acclimatize the llamas and alpacas of Chili. Four years 

 ago thirty-four of these animals, males and females, were imported into Hol- 

 land, and jjut into the royal park, Scheviningen, near the Hague, where they 

 have propagated freely. The climate does them no injury, and they merely 

 seek the shelter prepared for them when there is snow on the ground. — M. 

 Gaudichaud laid before the Academy his opinion on the disease which has lately 

 been so destructive to the jDotato. — M. Blanchet gave an account of the serious 

 consequences resulting from the process of whitening Brussels lace to the per- 

 sons employed in it. In this process the carbonate of lead is used ; and a large 

 portion of it is carried into the atmosphere, where it is inhaled, and thus pro- 

 duces a serious affection of the intestines. It is also very injurious to the sight 

 and to the hearing. — M. Leroy D'Etiolles submitted a new and improved litho- 

 tritic instrument. — Athenwum, No. 1051, p. 1306. 



Miss F. COUBAUX'S Coloured Map of Egypt will be given 

 in next Number, 



