Intelligence and Miscellaneous Articles. 4-13 



decomposition of animal substances, by the hydrated fixed alkalies, 

 into water, carbonic acid and ammonia, if they contain azote. It 

 results from the experiments of M. Reizet, that this process is not 

 entirely free from all chances of error. In the first place the mix- 

 ture of soda and lime retains atmospheric air confined in a peculiar 

 state of condensation ; this air cannot be expelled either by a cur- 

 rent of gas, nor under the influence of a vacuum. During combus- 

 tion, the azote of this air gives rise to ammonia, which is added to 

 that coming from the substance submitted to analysis. Faraday has 

 observed that non-azotized organic substances, even charcoal and the 

 metals which decompose water, yield ammonia when calcined with 

 potash in contact with air. 



Another chance of error in the process of MM. Varrentrapp and 

 Will results from the circumstance, that the alcohol in which the 

 perchloride of platina is dissolved, reduces this salt to the state of 

 insoluble protochloride ; this operation takes place very slowly, it is 

 true, but it is so considerable that the protochloride formed, mixing 

 with an ammoniacal salt of platina, adds to its weight, and conse- 

 quently sensibly increases the proportion of azote. It is not ex- 

 plained how MM. Varrentrapp and Will always obtained less azote 

 than indicated by theory in the substances which they analysed, since 

 the causes of error in their process tend to give an excess, unless du- 

 ring the operation azote is disengaged either in a free state, or in 

 some other form than of ammonia, or that this gas is not entirely 

 condensed. — Ibid. 



NEW DOUBLE SALT OF SODA AND PROTOXIDE OF PLATINA. 



MM. Litton and Schnedermann, endeavouring to discover an easy 

 and certain method of preparing the double cyanides of platina, passed 

 a current of sulphurous acid gas to perfect saturation through a solu- 

 tion of chloride of platina, and afterwards saturated the liquor with car- 

 bonate of soda. They thus obtained a very bulky precipitate, which 

 was nearly colourless, and this, after perfectly washing it, they submit- 

 ted to an attentive examination ; and they found it to be a double salt 

 of soda and protoxide of platina. When dry, this salt is a white powder. 

 It is very slightly soluble in water, and insoluble in alcohol. The usual 

 reagents do not at all indicate the presence of platina in the aqueous 

 solution. If hydrosulphuric acid be passed into it, or if it be mixed 

 with hydrosulphate of ammonia, it does not change even after a long 

 time has elapsed, or by increase of temperature ; but if there be 

 added at the same time an acid which decomposes the salt, the li- 

 quor becomes slowly coloured at common temperatures, and when 

 heated it soon becomes reddish-brown ; and afterwards sulphuret of 

 platina separates. The alkalies, do not decompose this salt; when 

 heated with potash or soda, it undergoes no sensible change. 

 Treated in a dry state with a solution of hydrosulphate of ammonia, 

 or of sulphuret of potassium, it suffers no change at common tem- 

 peratures, but by ebullition it becomes gradually coloured, is even- 

 tually completely dissolved ; and from this solution sulphuret of pla- 

 tina is precipitated by acids. 



