396 Intelligence and Miscellanies. 



a cheaper rate, the oxigenated water, the employment of 

 which will then become more common. 



The method which I follow is this : I take nitrate of ba- 

 rytes, which I put into a porcelain retort, to which I lute a 

 Welter's tube, and extend the latter under an inverted jar 

 of water. I then gradually heat the retort, and maintain it 

 at a red heat, as long as any nitrous acid and azotic gases 

 are disengaged, which indicates that a portion of nitrate of 

 barytes remains to be decomposed ; but from the moment 

 that the oxygen gas passes perfectly pure, I remove the fire 

 and let the retort cool. The product of this decomposition 

 is a deutoxide of barium, which possesses all its known prop- 

 erties, among which is that of slacking with water without 

 being heated, of disengaging oxygen, when boiled in that 

 fluid, and of being brought to the state of protoxide by a 

 strong heat. Its purity is easily proved by treating it with 

 sulphuric acid, for no disengagement of nitric acid ensues. 

 Pure nitric acid does not disengage deutoxide of azote. We 

 may thus obtain a deutoxide of barium, as well charged with 

 oxygen, and as pure, as that which is procured by the other 

 process. Its formation is, m fact, very natural ; the protox- 

 ide of barium, finding itself in contact with a great quantity 

 of oxygen gas in the nascent state, combines with it and re- 

 tains it, if the heat be not too great, afterwards to disengage 

 it. — Ann ales de Chimie, ^c. Sept. 1827. 



57. Precipitation of albumen by phosphoric acid. — Ber- 

 zelius and Engelhart have discovered that phosphoric acid, 

 prepared by dissolving phosphorus in nitric acid, evaporating 

 the solution in a platina vessel and heating it to redness, 

 would, when dissolved in water, precipitate both vegetable 

 and animal albumen very abundantly, but that the power of 

 the acid to cause this precipitation, diminished from day to 

 day, and was entirely lost in the course of a few days. The 

 same effects in all points ensued -with phosphoric acid ob- 

 tained by burning phosphorus in a bell glas, and dissolving 

 the acid thus formed in water. This change in the acid 

 took place as well in closed vessels of glass or platina as in 

 open vessels, nor was it accelerated by ebullition. 



The power of precipitation was renewed by evaporation 

 and heating to redness, but was again lost in the course of a 

 day. The cause of this phenomenon, (Berzelius observes,.) 

 it was impossible to discover. — Idem. 



