M. Berlandfc on a Conducting Surf ace for Electrotype. 451 



The hydrochlorate of hydroxylamine has the formula NH 3 0, HC1. 

 It crystallizes in distinct prisms. The sulphate, which also crys- 

 tallizes, has the formula 2NH 3 0, H 2 SO 4 . The nitrate is extremely 

 soluble, and could not be obtained in crystals. The oxalate crys- 

 tallizes from a hot saturated solution in beautiful prisms. It 

 has the formula 2NH 3 0, G 2 H 2 O 4 . 



Hitherto the body has not been obtained pure in the free 

 state. When a strong solution of one of its salts is treated with 

 caustic potash, a disengagement of nitrogen takes place with the 

 simultaneous formation of ammonia. The decomposition is es- 

 sentially expressed by the equation 



3NH 3 = NH 3 + 2N + 3H 2 O. 



If in a solution of this sulphate the sulphuric acid is exactly 

 precipitated by baryta-water, a solution of hydroxylamine is 

 obtained which is somewhat more stable. It can be boiled 

 without any material decomposition taking place; and a part of 

 the hydroxylamine passes off with the aqueous vapour. 



Hydroxylamine is an oxygen base which differs from the 

 metallic oxides in the mode in which it unites with acids. While 

 the latter unite with acids with liberation of water, hydroxyl- 

 amine, like ammonia, unites directly with the acids. Hydroxyl- 

 amine is an ammonia in which an atom of hydrogen is replaced 

 by the radical HO. To this radical the name hydroxyle has 

 long been given; and the compound NH 3 is as much entitled 

 to the name hydroxylamine as the compound NGH 5 to the name 

 methylamine. 



Berlandt* describes the following method of giving a conduct- 

 ing surface to a body which is to be electrotyped. The impression 

 is wetted with dilute alcohol to avoid the formation of air-bubbles, 

 then washed with distilled water, and while still wet a solution 

 of nitrate of silver (one in four of water) is poured over it ; in a 

 few minutes the excess of liquid is poured off, and a solution of 

 green vitriol (one in three) poured over it. In five minutes this 

 is allowed to drain off; the impression is again treated with 

 solution of silver, and then with vitriol solution three or four 

 times, till the surface of reduced silver has a whitish-grey colour. 

 The impression is then washed with pure water and subjected to 

 the action of the electric current. At the first moment the entire 

 cast is covered with a thin layer of copper of dark brown colour, 

 and in a few minutes the layer, which firmly adheres, acquires a 

 natural copper-colour. 



* Archiv der Pharm. vol. cxxi. p. 54. 



