396 New Scientific Books. [May, 



water, when a large quantity of arseniate of iron will be left. Add to 

 the solutions successive portions of carbonate of soda until a greenish 

 precipitate appears, at which time all the arsenic and iron will be se- 

 parated, and part of the copper ; the rest of the copper may be 

 separated by sulphuretted hydrogen, and the clear solution thus ob- 

 tained, when boiled with sub -carbonate of soda, yields the carbonate 

 of nickel. 



Thus obtained, the carbonate of nickel contains a little cobalt ; to 

 separate the latter, the precipitate, as obtained above by boiling with 

 sub-carbonate of soda, is to be well washed and diffused whilst moist 

 in water, and a current of chlorine passed into it until in excess : the 

 excess of chlorine is to be allowed to dissipate and the solution filtered ; 

 it now contains not the smallest trace of cobalt, that remaining as a 

 hydrated peroxide, with a certain portion of nickel in the same state. 

 If in the mixed carbonate of nickel and cobalt, the latter is in excess; 

 the residue, after the action of the chlorine, is pure hydrate of cobalt, 

 and the solution contains the nickel with a small quantity of cobalt. — 

 (Ann. de Chim. xxv. 95.)* 



VIII. Prussian Blue. 



Mr. Badnall, of Leek, has taken out a patent for improvements in 

 dyeing with Prussian blue. The improvement consists in preparing 

 the Prussian blue, by mixing it in fine powder with strong muriatic 

 acid, and stirring it until the whole becomes a smooth homogeneous 

 mass of a semi-gelatinous consistence. We notice it here merely to 

 remark on the circumstance that an agent in which Prussian blue is 

 insoluble, should be found useful in enabling it to combine with silk, 

 cotton, wool, &c. The pure ferro-prussiate of iron is soluble in water, 

 but the addition of a small portion of muriatic acid immediately 

 precipitates it ; wash away the acid by pure water, and the pigment 

 becomes soluble again; re-acidify, and it re-precipitates. — (Institution 

 Journal.) 



Article XV. 

 NEW SCIENTIFIC BOOKS. 



PREPARING FOR PUBLICATION. 



An Appendix to Capt. Parry's Second Voyage of Discovery, con- 

 taining the Natural History, &c. 4to. 



The private Journal of Capt. G. F. Lyon, of his Majesty's Ship 

 Hecla, during the recent Voyage of Discovery, under Capt. Parry, 

 8vo. 



Narrative of the Proceedings of the Expedition to explore the 

 Northern Coast of Africa, in 1821, 1822. By Capt. W. F. Beechey, 

 RN. and H. W. Beechey, Esq. <ko. 



Narrative of Four Voyages of Survey in the Inner Tropical and 

 Western Coast of Australia, between the Year* 1SJ 7 and 1822. By 

 Philip Parker King, RN. Commander of the Expedition. 4to. 



* Dr. Thomson's process for obtaining pure oxide of nickel is much more simple, 

 and I believe as efficacious as the above. — Edit. 



