672 APPENDIX* 



lines wide. The shut end is to be drawn out into a long point, 

 which is hermetically sealed. To the open end of this tube is 

 fixed, by means of a good cork, so as to be air-tight, the bent 

 tube, a, b, c, somewhat resembling Liebig's potash tube ; but 

 having only the three bulbs, a, b, c. The central bulb, b, is fil- 

 led with a quantity of muriatic acid of commerce to absorb the 

 ammonia. The avidity of muriatic acid for ammonia is so great 

 that there is no risk of any loss. 



The hydrate of potash or soda is to be mixed with so much 

 quicklime, that the whole can be easily reduced to powder, and 

 that it should not melt, but only soften a little in the decompos- 

 ing tube. As hydrate of soda has a smaller atomic weight than 

 hydrate of potash, it is to be preferred. One part of hydrate of 

 soda mixed with two parts of anhydrous lime will answer. When 

 hydrate of potash is used, it should be mixed with thrice its weight 

 of quicklime. The best way is to heat the hydrate of alkali to 

 redness, so as to bring it into a state of fusion. It ought, then, 

 to be rapidly pounded in a warm mortar, and intimately mixed 

 with the lime. And while still dry, it must be put into a well- 

 stoppered phial and kept for use. 



The decomposing tube is now about half-filled with this mix- 

 ture. The quantity of the organic body containing azote requi- 

 site varies with the quantity of azote which it contains. Ac- 

 cording to Varrentrapp and Will, it is not necessary to use more 

 than six or less than three grains. It is to be mixed with the 

 hydrate of soda and lime in a warm and dry mortar, and consi- 

 derable precautions are necessary to prevent any loss. 



The muriatic acid tube is attached to the decomposing tube by 

 a good cork ; and care must be taken to ascertain that the ap- 

 paratus is air-tight. The open end of the tube, which contains 

 no organic matter, is first to be heated to redness, in order to pre- 

 vent any of the organic matter from passing without being de- 

 composed completely. The cork must be kept as warm as pos- 

 sible, that no moisture may lodge about it ; because such a de- 

 position would cause a loss of azote by absorbing some ammo- 

 nia. 



As soon as the open end is red hot, the fire is removed farther 

 back. The oxygen of the alkaline hydrate forms carbonic acid 

 with the whole or with a portion of the carbon in the organic 

 body, while the hydrogen combines with the azote and forms am- 



