154 Scientific Intelligence, 



the double chloride of chromium and potassium. This double 

 chloride was prepared by reducing potassium dichromate with 

 alcohol and hydrogen chloride, adding the necessary additional 

 quantity of potassium chloride, filtering, evaporating to dryness 

 and heating the mass until dehydrated. Double the necessary 

 amount of magnesium, in the form of filings, was then added to 

 the pulverized mass, that is 50 grams of filings to 260 of the 

 double chloride, and the whole was placed in a Hessian crucible, 

 covered and exposed to a high temperature in a wind-furnace. 

 After cooling the mass was treated first with water to remove the 

 potassium and the magnesium chlorides, and then alter deeanta- 

 tion, with dilute nitric acid to remove the excess of magnesium. 

 The chromium which remained undissolved weighed after drying 

 on the water bath 27 grams. It could not be collected on a 

 filter, since it was so finely divided as to run through. It was a 

 bright gray powder appearing as white or yellowish-white 

 crystals under the microscope, having a metallic luster. Rubbed 

 in an agate mortar it gave a streak resembling lead. At 16°, it* 

 relative mass was 6*7284. A powerful steel magnet was without 

 action on it. It fused only in a Devil le's blast-furnace, giving a 

 mass having a silver-white fracture. Analysis showed it to con- 

 tain 99*57 per cent chromium. — Ber. Bert. Chem. Ges., xxiii, 

 3127, November, 1890. g. f. b. 



6. On the Production of Urea from Albumin. — The attempts 

 which have been made to obtain urea by the oxidation of albu- 

 min, have given no positive result. Drechsel now shows that 

 when casein is boiled with concentrated hydrochloric acid and 

 stannous chloride, a base is produced having the formula 

 C 6 H ir N 8 0, and which he calls lysatine. This on boiling with 

 baryta water, affords urea. Hence he regards the lysatine and 

 of course the urea from it, as due not to an oxidation but to a 

 hydrolysation of the albuminate. — Ber. Berl. Chem. Ges., xxiii^ 

 3096, October, 1890. G. F. b. 



7. On Azoimide or Hydrazoic acid. — A remarkable compound 

 of nitrogen and hydrogen N 3 H has been discovered by Ctjrtius, 

 which bears a striking analogy to the haloid acids and is theo- 

 retically formed by the action of nitrous acid upon diamide, a& 

 nitrogen is by its action upon ammonia. In the latter case the 

 reaction is 



NH 4 C1 + NaN0 9 =N a + (H 2 0) a + NaCl 



while in the case of diamide it is 



N 2 H 4 HC1 + NaN0 2 =N 8 H + (H 2 0) 2 + NaCl. 



In fact, however, the production of the new substance is much 

 less direct. By the action of diamide hydrate upon benzoylgly- 

 collic ether, or upon hippuric ether, benzoyl diamide or hippuryl 

 diamide is produced. By the action of sodium nitrite upon ben- 

 zoyl diamide, benzoyl azoimide is obtained ; and this on boiling 

 with sodium hydrate gives sodium azoimide, 



