458 M. Helkenkamp on two new double Salts of Cyanogen. 



Tlie quantity of proteine substances, albumen, and easeine 

 together, remains almost constant. The quantity of sugar of 

 milk is greatest at midday, and decreases towards evening. 



The specific gravity of milk is no criterion of its value. A 

 higher specific gravity may indeed be caused by sugar of milk 

 and proteine substances ; but a lower specific gravity does not 

 necessarily arise from an increase in the quantity of butter, but 

 also by a greater amount of water. 



The importance of this difference, not only for physiological 

 chemistry, but also for dietetics and practical agriculture, is ' 

 obvious when we consider that a pound of the morning milk of 

 the cow contains about 3 drachms of butter; a pound of the 

 evening milk, on the contrary, 7 drachms. 



For the separation of nickel from iron, Schwarzenberg pro- 

 poses a method founded on Herschel's process ; that is, to neu- 

 tralize the dilute acid solution of the mixed oxides with carbon- 

 ate of ammonia, and to precipitate the oxide of iron by boiling. 



Helkenkamp describes two new double salts of cyanogen with 

 copper and ammonia. To hydrocyanic acid, a solution of hydrated 

 oxide of copper in ammonia is added until the smell of the latter 

 prevails. The mixture is then gently heated, and the addition 

 of the ammoniacal copper solution is continued until the liquid, 

 which at first was yellow, has become blue. After some time 

 green rectangular laminae, possessing a splendid lustre, appear 

 in the liquid. On analysis, these gave numbers corresponding 

 to the formula 



2Cu2 Cy + Cu Cy + 2NH3 + 2H0. 



When these crystals are treated at a gentle heat with a mixture 

 of ammonia and carbonate of ammonia, they dissolve into a blue 

 liquid, from which, on cooling, lustrous blue laminge separate. 

 These are distinguished from the former by containing 2 equivs. 

 of water less. Their formula is 2Cu2 Cy -\- Cu Cy + 2NH3. 



Fuchs had found, that burnt lime exposed to the air formed a 

 compound of caustic lime with carbonate of lime. Wittstein's 

 experiments do not confirm this. He found that caustic lime 

 which was exposed to the air, and from time to time powdered, 

 increased regularly for forty months; on exposure for eight 

 months after that time, no further increase was perceived. It 

 consisted, then, deducting the impurities, of dry carbonate of 

 lime. 



In a research which he had undertaken on the Influence of 

 the Nitrates on Vegetation, M. George Ville was led to seek a 

 simple method of determining the nitrates. This he gives in the 



