202 Bibliography. 



or fused with a little carbonate of potash. Metallic silver, perfectly 

 pure, is thus obtained with great ease and rapidity. The oxide of sil- 

 ver thus prepared we have used to dissolve in cyanide of potassium, 

 for the purposes of the electro-metallurgist, with entire success. 



Prof. Liebig has a very important paper on the preparation and uses 

 of cyanide of potassium, a salt now of great value from its employ- 

 ment in gilding and silvering in the moist way, and recommends 

 the following process. The yellow prussiate of potash is dried (until 

 it falls to a white powder) on a hot iron plate, and then mixed with 

 dried carbonate of potash in the proportion of 6 oz. of the latter sub- 

 stance to 16 of the former, and the mixture thrown at once into a 

 Hessian crucible previously heated to redness, and kept at that tem- 

 perature until the mixture is completely fused with lively effervescence. 

 It is stirred with a glass rod, and when it has a clear amber color is 

 taken from the fire ; the brown flocks of matter (which are metallic 

 iron) seen floating about in the liquid mass settle, and the clear fluid 

 is poured on a marble slab, broken up, and it is fit for use. The 

 reaction which takes place in this process gives us a portion of cyan- 

 ate mixed with the cyanide, which interferes with no one of its uses. 

 Liebig remarks that it is difficult to conceive with what extreme facility 

 the cyanide of potassium deprives certain metallic oxides and sulphurets 

 of their oxygen and sulphur, for of all known substances, it approaches 

 nearest in that respect to pure potassium. He then describes the use 

 of this salt as an agent in quantitative analysis, where it renders easy, 

 many before difficult processes. 



13. The EncyclojJcedia of Chemistry, Theoretical and Practical, pre- 

 senting a complete and extended view of the present state of Chemical 

 Science ; by James C. Booth and Martin H. Boye. Philadelphia ; Ca- 

 rey & Hart. 8vo, published in numbers, with plates and wood cuts. 

 Nos. I and II. — This work is understood to be founded mainly on the 

 celebrated Chemical Dictionary of Liebig and Wbhler, while it contains 

 all that is most valuable in Ure and other English writers. The well 

 known accuracy and knowledge of its conductors, is a sufficient guaran- 

 tee for the value of the work. 



It abounds in information useful to the manufacturer and artisan, and 

 yet contains much to command the attention of the chemical student. 

 We have read with much satisfaction the article on Affinity. Under 

 Acids is a full table of organic and inorganic acids, with their sources, 

 formula? and authority. The tables under Alcohol are more full and 

 varied than can be found elsewhere in our language, and the entire ar- 

 ticle under that head is most excellent, while the article on Agriculture 

 embodies in a condensed form a great amount of valuable matter, em- 



