Method of determining Nitrogen in Organic Compounds. 219 



cork which need not be previously dried. The form of the 

 bulb apparatus chosen will allow of its being easily and per- 

 fectly washed out, while there is not the least danger of any of 

 the ammonia not being absorbed. It is represented in the an- 

 nexed wood-cut, 



and is easily constructed. It is filled by inserting the pointed 

 end g into muriatic acid of the usual strength (specific gravity 

 1'13), and drawing it in with the mouth at d until the stand 

 of the liquid attains the level indicated by the shading. 



For decomposing the nitrogenous substances and oxidizing 

 their carbon and hydrogen, we employ a mixture of the hy- 

 drate of soda or of .potash with caustic lime, in such propor- 

 tions, that, although acting energetically, it does not melt at a 

 red heat, but merely frits slightly: this mixture has at the 

 same time the advantage of being of an easy pulverizable na- 

 ture, of not attracting moisture very rapidly, and is as easily 

 managed as the oxide of copper or chromate of lead. The 

 best mixture is that of 1 part by weight of hydrate of soda to 

 2 parts of caustic lime (one part of hydrate of potash requires 

 three of caustic lime, but this latter mixture attracts moisture 

 more rapidly, and has other disadvantages which will be sub- 

 sequently mentioned), and is easily prepared by slacking the 

 caustic lime with a solution of soda of known concentration ; 

 it is then heated in a crucible and powdered finely ; or the 

 melted and cooled hydrate of soda is pounded quickly in a 

 warm mortar, and well mixed with the finely powdered cau- 

 stic lime in the above proportions. The mixture is again ex- 

 posed to a gentle heat to drive off all moisture, and preserved 

 in a well-stopped bottle with a wide mouth. 



When the substance to be examined has been reduced to 

 a fine powder, dried and weighed, the previously cleansed 

 and dried tube of combustion is filled one half with the mix- 

 ture of alkali and lime, in order to have a fixed measure for 

 the (|uantity with which the substance to be analysed is to be 

 mixed. The quantity of the latter which is requisite for a 

 combustion, can be taken according to the supposed amount 

 of nitrogen it contains; it is, however, rarely requisite to em- 



