Intelligence and Miscellaneous Articles. 77 



contrary was proved by an examination, which led to the inference 

 that the extremities of the piles having been charred, the straps of 

 iron closely wedged between them, and the stratum in which they 

 were imbedded, must have been subjected to a galvanic action, which 

 in the course of some six or seven hundred years gradually produced 

 the effects recorded in the present paper. T. J. H. 



CAOUTCHOUC 



Few persons are perhaps aware of the comparatively late intro- 

 duction of Indian Rubber into this country. The following notice 

 is appended by Dr. Priestley to the preface to his Familiar Intro- 

 duction to the Theory and Practice of Perspective, printed in 1770; 

 and it will be observed that no name is given to the substance de- 

 scribed : " Since this work was printed off, I have seen a substance 

 excellently adapted to the purpose of wiping from paper the marks 

 of a black-lead pencil. It must, therefore, be of singular use to 

 those who practise drawing. It is sold by Mr. Nairne, Mathema- 

 tical Instrument Maker, opposite the Royal Exchange. He sells a 

 cubical piece, of about half an inch, for three shillings ; and he says 

 it will last several years." 



FORMATION OF JETHER BY FLUORIDE OF BORON. 



MM. Wbhler and Liebig in order to examine the formation ot 

 aether as stated by Desfosses, passed fluoboric gas into absolute al- 

 cohol. Much of it was absorbed, great heat was excited, and the 

 solution became gelatinous, transparent and fuming. A small portion 

 was saturated with potash ; no aether separated, but the liquid had a 

 peculiar odour, totally different from that of aether, but very agree- 

 able; when distilled after dilution with water, it yielded more alco- 

 hol. That which had been saturated with fluoboric gas, when dis- 

 tilled gave a colourless liquor, from which water separated a notable 

 quantity of pure aether. 



Fluosilicic gas when passed into alcohol to saturation, gave no 

 gelatinous mass, nor the smallest quantity of aether; as Berzelius has 

 already stated. The action which has been attributed, in the for- 

 mation of aether by sulphuric acid, to the sulphovinic acid produced, 

 appears therefore to be very problematical. — Ann. de Ckim. torn, 

 xlix. p. 30. 



PEROXIDE OF BARIUM. 



The hydrated peroxide of barium employed to prepare peroxide 

 of hydrogen, may be obtained, according to MM. Wohler and Lie- 

 big, with the greatest facility by the following process. Heat caustic 

 barytes in a platinum crucible, by means of a spirit lamp, until it is 

 nearly red hot, and then throw in, by small quantities at a time, 

 chlorate of potash ; incandescence takes place, and the protoxide 

 becomes peroxide of barium. When the mass is cold, dissolve the 

 chlorideof potassium by solution in cold water; the peroxide becomes 

 a hydrate during this operation, and remains in the state of a white 



