Intelligence and Miscellanemis Articles. S17- 



duced a certain quantity of pyrogenous, essential chlorinated oil, 

 the action of which on the animal oeconomy is extremely hurtful. 



4th, It is indispensable to free chloroform from this chlorinated 

 essential oil, by not continuing the rectification too long. — Journ. 

 de Pharm. et de Ch.. Juillet 1849. 



ON THE PREPARATION OF NITROGEN GAS. 

 BY M. B. CORENWINDER. 



The preparation of nitrogen is attended with several inconveni-. 

 ences : there is no one of all the processes employed by which it can 

 be obtained rapidly and pure, without much precaution and the use 

 of complicated apparatus. This circumstance induced the author to 

 publish the method by which he obtains in a few minutes a large 

 quantity of this gas, and in a state of absolute purity, as shown by 

 experiments related below. 



This process is derived from the decomposition of nitrite of am- 

 monia, which, as is well known, is resolved by heat into nitrogen 

 and water ; but as this salt is difficult to prepare, it is replaced by a 

 mixture of alkaline nitrite of potash and hydrochiorate of ammonia, 

 a mixture which contains the elements of nitrite of ammonia and 

 chloride of potassium. 



In order to obtain the nitrite of potash in a proper state, it is 

 requisite to employ a solution of caustic potash, of density 1*38, and 

 to pass into it nitric oxide obtained from the decomposition of one 

 part of starch by ten parts of nitric acid, until a distinctly acid pro- 

 duct is obtained, and afterwards to add to it caustic potash, so as 

 to render it decidedly alkaline. 



The nitrite thus prepared may be kept without undergoing alte- 

 ration, so that a quantity of it may be prepared ; and when nitrogen 

 is required, it is sufficient to mix concentrated solutions of one vo- 

 lume with three volumes of hydrochiorate of ammonia, and to heat 

 the mixture in a retort by a charcoal fire ; the disengagement soon 

 commences, and continues with perfect regularity. 



As it is necessary, in order to have the gas pure, that the nitrite 

 should be alkaline, it will be expected that a small quantity of am- 

 monia will be evolved ; but this disengagement is unattended with 

 any inconvenience ; if the nitrogen gas be required completely de- 

 prived of this alkali, it is sufficient to pass it through water acidu- 

 lated with sulphuric acid contained in a bottle. 



The following experiments left no doubt as to the purity of the 

 nitrogen gas thus obtained : — 



1st. After having deprived it of ammonia in the manner above 

 stated, it was passed into a bottle containing a mixture of zinc, 

 sulphuric acid and water, and consequently in the presence of nas- 

 cent hydrogen. 



The experiment was continued for a considerable time ; and when 



