112 Dr. Kane on Combinations derived from Pyroacetic Spirit. 



the crystals had been contaminated in the retort. The boiling in alcohol must 

 be repeated until the residual salt no longer gives any trace of iodine when 

 moistened with nitric acid. It may then be considered pure; as, though prepared at 

 different periods, it has always given the same analytical results. The salt appears 

 as a mass of small white crystalline grains, of an amylaceous appearance, neutral to 

 test paper. When heated it takes fire, burning with a pure phosphorous flame, 

 and throwing off copious fumes of phosphoric acid ; when the phosphorus ceases 

 to be emitted the residue is black, but further heated it gives a pure white 

 residue of phosphate of baryta. When moistened with nitric acid, and heated, a 

 very violent reaction ensues, and unless great caution be employed, some of the 

 materials are projected out of the vessel : in any case some phosphorus is lost, 

 being disengaged in the gaseous form. When this salt has been once obtained 

 solid, there is great difficulty in dissolving it completely in water again, although 

 no marked difference of composition can be observed between the portion which 

 dissolves and that which remains unacted on. 



0.700 of the salt was moistened with nitric acid, and very cautiously decom- 

 posed by heat in a platinum crucible. The action was violent, but without any 

 projection of the solid materials. The residue \ s treated with nitric acid until 

 it remained white; it weighed 0.520, giving 74. J per cent. It was dissolved 

 in dilute nitric acid, and the solution precipitated by sulphate of soda. There 

 was obtained 0.467 of sulphate of baryta, corresponding to 43.8 of baryta, from 

 100 of the salt employed. 



0.368 of salt similarly treated gave 0.277 residue; which, dissolved and treated 

 as above, gave 0.247 sulphate of baryta, or 67.1 per cent., containing 44.0 of 

 baryta. 



I. 0.469 material gave 

 0.169 water, 

 0.346 carbonic acid; 



corresponding to 



Hydrogen ^ 4.00 

 Carbon =: 20.40 per cent. 

 II. 0.566 material gave 

 0.186 water, 

 0.399 carbonic acid ; 



