Chemical Science. • 181 



thought at first, that these salts were formed of cyanurets and 

 sulphuric acid, but as the acid prussiate of the prot-oxide of 

 iron (ferro-prussic acid of Porret,) produces the same phee- 

 nomenon, it appeared evident that the bases were oxidated, 

 and that the cyanuret was combined with hydrogen. These 

 results make part of a long Memoire which will appear in the 

 Mimoires de VAcademie. — Annates de Chim. XIV. p. I9O. 



7. Preparation ef Phosphorus. — M. Julien Javal, in pre- 

 paring phosphorus lately, observed, that failure took place to 

 a certain extent, when phosphoric acid was used, in conse- 

 quence of the volatility of this substance at high temperatures. 

 On making the phosphoric acid into bi-phosphate of lime, the 

 process went on well again. As a practical result from his 

 experiments, he advises that on adding the sulphuric acid to 

 the burnt bones in the usual way, only two of the former should 

 be put to five of the latter, in which case a proper bi-phosphate 

 of lime will be obtained. If, by any accident, the prepared 

 bi-phosphate should contain an excess of acid, or rather free 

 acid, then he finds it necessary to cover over the mixture of it 

 and charcoal, when in the retort, with a stratum of charcoal 

 alone, and to get this part of the retort hot before the lower. 

 With these precautions the phosphoric acid which rises is 

 decomposed in passing through the hot charcoal, but other- 

 wise it will be condensed, unacted on. 



8. Metallic Vegetations. — " M. Goldsmith places a few filings 

 of copper and of iron on a glass plate, at a certain distance 

 one from the other. He then drops a little nitrate of silver on 

 each parcel ; the silver soon begins to precipitate, whilst the 

 iron and copper oxidize, and become coloured; then, by a 

 small wooden point, the ramifications are arranged at will, 

 whilst the flame of a taper being placed under the plate, in- 

 creases the evaporation, facilitates the re-action of the sub- 

 stances, blackens the lower side of the plate, and tluis forms 

 .as it were a design." — Annates de Chim. 14. p. 84. 



9. Muriate of Potash in Rock Salt.--'la consequence of 



