538 ANNUAL KECOKD OF SCIENCE AND INDUSTRY. 



action of its vapor upon the operatives. He regards the idea, 

 meantime, as a good one, and thinks the substitution of some 

 less volatile and injurious liquid (as petroleum naphtha) for 

 the bisulphide is well worth trying. 15 (7, XVII., 1874, 272. 



gatjdin's polishing paper. 



Messrs. Gaudin & Co., of Paris, have recently introduced 

 a new polishing paper, made with a mixture of silex and 

 alumina melted together and reduced to a fine powder. This 

 they claim is much superior to emery paper or any other 

 substance used for the same purpose. It really constitutes 

 an artificial emery or corundum, but is in a form much more 

 convenient for application than the natural substance. 1 .Z?, 

 May 2,61. 



PREPARATION OF ABSOLUTE ALCOHOL. 



Professor J. L. Smith informs us that alcohol of 98 per 

 cent, can be obtained by shaking up the strongest commer- 

 cial alcohol with freshly burned lime in a tightly closed ves- 

 sel, renewing the operation every day for a week or ten days, 

 when the bottles are allowed to remain at rest for a few days 

 for the hydrate of lime to settle, and the original alcohol can 

 be drawn off, free from lime, and of 98 per cent. To obtain 

 absolute alcohol the last draft is to be put into a convenient 

 flask, with the addition of lime in coarse powder and an in- 

 verted Liebig condenser attached, so that the alcohol will 

 run back into the flask when condensed. This is then dis- 

 tilled over, and will mark 100 per cent. 1 A 9 November 20, 

 1874,235. 



FILLING HOLLOW BRASS ARTICLES WITH MOLTEN IRON. 



Atkins, of Birmingham, casts molten iron in hollow brass 

 objects, without danger of melting them, by simply immers- 

 ing them in water, which prevents their temperature from 

 rising above 212. To make weights in this way the brass 

 shell is imbedded in iron filings instead of water. 13 C, 

 November 1, 1874, 1364. 



CEMENT FOR MARBLE AND ALABASTER. 



It is said that the point of fracture of articles cemented 

 with the following mixture is difficult to find, and that the 



