390 Mr Self, On a soluble colloidal form, etc. 



the hydrolysis of the aqueous ferric chloride and more especially 

 the action of free ammonia in the dialyser on the ferric phosphate 

 carrying away ammonium phosphate. 



The dialysed solution is tasteless, of a reddish brown colour, 

 and without action on litmus. Solutions of alkaline chlorides and 

 of most other salts cause the solution to gelatinise. With silver 

 nitrate a yellow precipitate consisting for the most part of ferric 

 phosphate but containing a minute quantity of silver phosphate 

 is produced. The electric conductivity of the solution was not 

 accurately determined but was very small, approximating to that of 

 the distilled water used. This is in accordance with its behaviour 

 with such reagents as potassium . sulphocyanate which gelatinises 

 the solution but produces no change of colour, thus indicating the 

 absence of free iron ions in the solution. Potassium ferrocyanide 

 also gelatinises the solution, the separated material being slightly 

 darkened but no blue colour is produced. On the other hand 

 sulphuretted hydrogen and also ammonium sulphide give black 

 precipitates. 



The rays emitted from radium bromide have no visible effect 

 on the solution. 



The soluble colloidal forms of aluminium and of chromium 

 phosphate were prepared in a precisely similar way to the ferric 

 phosphate. The solutions however are weaker, especially the 

 chromium phosphate. Their behaviour with reagents and also 

 with salts generally is similar to that of ferric phosphate. 



