212 NITROGEN BODIES OF MODERN CHEMISTRY. 



or, at most, only sliglitly soluble in acetic etber. On the other bandj 

 cotton prepared at a higher temperature, which explodes irapeit'ectly, 

 has ju«t this property of dissolving in alcoholized ether. 



In {)ure alcohol, entirely free from water and ether, collodion-cotton 

 dissolves imperfectly or not at all. If the cotton be wet with pure alco- 

 hol the superfluous alcohol may be poured off and ether added ; the cot- 

 ton will now dissolve in common ether. The cotton wet with alcohol 

 begins to dissolve in the ether, and the liquid thus obtained is usually 

 tiltered through cotton in its natural state to remove any fibers which 

 may remain undissolved, and the liltered liquid is the so-called collo- 

 dion, adhesive ether, i. e., the solution of tri-nitrocelluline in alcoholized 

 ether. This collodion may be saturated with gun-cotton to a somewhat 

 thick liquid. Allowed to evaporate on glass, it leaves a film of collo- 

 dion. This solution of collodion is applied to burns when there is no 

 blood or moisture. In scalds, if not very severe, it does good service. 

 In order to avoid painful contractions of the skin, it is best applied with 

 a solution of castor-oil in alcohol. This imparts to it a degree of pli- 

 ancy which causes it to yield to the motions of the skin without causing 

 pain. 



There is a whole series of bodies besides gun-cotton belonging to the 

 same class; e. r/., uitro-maunite, obtained from mannite, from mamia. If 

 manna, such as is procured from the ash-tree, is dissolved in uitro-sul- 

 phuric acid, and left standing a while until red vapors appear, and then 

 poured into cold water, a white, powdery, crystalline mass is precipitated ;■ 

 this is nitro-manuite. This substance explodes tolerably well. An 

 attempt was made to substitute it for fulminate of mercury, but the at- 

 tempt was abandoned. Nevertheless, it is destined to important uses 

 in the industrial arts. 



Ordinary cane-sugar treated in the same manner, dissolved in nitro- 

 sulphuricacid,!. <?., a mixture of red faming nitric acid and IsTordhausen oil 

 of vitriol, kept ice-cold, and when the red fumes appear, poured into cold 

 water solidifies, and when it softens can be dravrn into threads of almost 

 silken luster. It is certain that the solutions of it in alcohol and ether, 

 even in the water, in which it is preserved, taste extremely bitter. 

 This body is called uitro-saccharine. By the mere substitution of 

 uitryl for one atom of the hydrogen, the sweet taste of the sugar is 

 changed to one thus iuten::cly bitter. How complete a transformation 

 takes place is shown by this, that nitro-saccharine is incapable of the 

 vinous fermentation, is no longer a means of nourishment, but has be- 

 come a poison, a foreign substance, which bids defiance to assimilation 

 and digestion as well as fermentation. 



When starch is treated in the same manner, the purest starch, from 

 potatoes, rice, or wheat, when it is stirred into the mixture of acids, it 

 cannot be said to dissolve, but a glutinous swelling takes place, and 

 when on the appearance of the red vapor the mass is poured into cold 

 water, a shining white substance is deposited, which is called xyloidine. 



