M58 SCIENTIFIC GOSSIP. 



rub well over the glass, afterwards waslaing till all the acid is removed. 

 A thin film of glass is thereby dissolved off, and a fresh bright surface 

 exposed. 



To Smokers. — M. Melseus advises smokers to put in the barrel of their 

 pipes or of their cigar-holder, a piece of cotton impregnated with a mixture 

 of tannic and citric acids. The smoke passing through the cotton, leaves 

 the nicotine, which combines with the two acids. 



The EartKs Axis. — The alteration of the earth's axis of rotation by- 

 tidal friction has by some physicists been assumed as a sufficient explanation 

 of changes in the earth's climate. Mr. Stone, of the Royal Observatory, 

 Greenwich, has investigated the question; and, in the Monthly Notices of 

 the Eoyal Astronomical Society, has demonstrated the failure of that theory 

 to account for the phenomena. Geologists Avho have built up elaborate 

 arguments on that assumption will have in consequence to reconsider their 

 conclusions. 



Manufacture of Oxygen. — It is stated that the cost of Oxygen procured 

 by the decomposition of sulphiuric acid by heat, will be no more than about 

 2^d. per cubic yard! 



Obtaining sections of soft tissue for the Microscope. — At the monthly 

 meeting of the Quekett ]\Iicroscopic Club at University College, on 2Gth 

 April, Dr. Halifax described an ingenious process for obtaining thin sections 

 of insects, soft vegetable tissues, minute seeds &c., by immersing them in 

 melted wax, and when cold slicing them upon the ordinary section table. 



Drilling Glass. — There is an old and Avell-known method of drilling 

 glass by means of a file dipped in oil of turpentine. A correspondent of 

 the Chemical News states that a file dipped in diluted sulphuric acid (1:5) 

 drills glass very much easier than when wetted with turpentine, while at 

 the same time, strangely enough, the file or drill is less acted upon. 



Uses of Epsom Salts. — A strong solution added to whitewash will 

 produce a beautiful white for ceilings of rooms. A small quantity mixed 

 with starch increases cousiderabl}' its stiffening powers, and renders the 

 article to a certain extent fire-proof. 



JOHN NOBLE, F. C.S. 



