276 Scientific Intelligence. 



neutralizing alizaric acid with carbonate of lime, and evaporating to 

 crystallization. It crystallizes in prisms possessing great brilliancy. 

 Aliearate of baryta, prepared in the same way by means of carbonate 

 of baryta, cystaliizes in silky needles. Alizarate of silver, prepared 

 by double decomposition, is soluble in boiling water, from which it 

 crystallizes as the solution cools. Alizarate of lead is insoluble. By 

 subjecting alizaric acid to heat, it is volatilized, and forms a sublimate 

 in the shape of long white needles, to which the name of pyro-alizaric 

 acid is given. By the solution in water, pyro-alizaric acid appears to 

 be again converted into alizaric acid. Rubiacin was found to be C 31 , 

 H 9 , 10 , and Rubiacic Acid C 31 ,H 9 , 16 . Alpha and Beta resin 

 were next examined, as were also the other constituents: and the au- 

 thor then proceeded to examine the part which each material plays in 

 the process of dyeing : from which it is satisfactorily proved that alizarin 

 is the substance producing the color; and the advantages of convert- 

 ing madder into garanein consists in removing the resins and those 

 bodies which are not only useless but injurious, and in separating aliza- 

 rin from those salts with which it is in the madder root in close com- 

 bination. 



7. On the Alloys of Tungsten with Copper and other Metals ; by 

 Dr. Percy, (Proc. Brit. Ass., Athen., No. 1086,)— Since the introduc- 

 tion of some processes by which tungsten has been separated from its 

 ores, and from its combination with tin and other metals in nature, 

 numerous experiments have been made with the hope of employing it 

 usefully. From the peculiar nature of tungsten it has been thought 

 that it would have the property of giving greater hardness to the 

 metals with which it might be alloyed, and also of protecting them 

 from oxydation. It was with this hope that Dr. Percy made an exten- 

 sive series of experiments, — alloying copper, brass, German silver, and 

 other metallic bodies with tungsten. In no case, however, has the re- 

 sult been of a satisfactory character. 



• 8. Analysis of Wrought Iron produced by Cementation from Cast 

 Iron ; by Prof. Miller, (Proc. Brit. Assoc, Athen., No. 1086.)— It is 

 to be noticed that considerable change in the specific gravity occurred 

 in the iron after cementation : it was forged, and then found to have 

 increased in density ; the brittle iron had a specific gravity of 7-684, the 

 malleable 7*718. The results of analysis were briefly these :— the 

 quantity both of carbon and* silicon are" materially diminished by the 

 cementation, though still the proportion of both is materially greater 

 than in good bar iron. It also appears that the portion of carbon which 

 is insoluble in acids is partly the same both before and after the iron 

 lias been rendered malleable, the diminution being confined almost to 

 that p ortion of carbon which was chemically combined with the metal, 

 and whicb, therefore, would be in a state for propagation through tlr 

 mass more readily by cementation. 



9. Gutta Percha, (Proc. Brit. Assoc, Athen., No. 1086.)— Mr. 

 Whishaw read a paper giving an explanation of the various applica- 

 tions of gutta percha; numerous specimens of which, in the shape of 

 thread, cord, tubular staves, driving bands, constables' staves, stick 

 whips, inkstands, medallions, shields, water buckets, stereotype plates, 

 and almost every other description of article, both useful and ornamen- 





