524 Mr. Gladstone on the 



I. II. III. 



Xyloidine employed . . 4' 7 7 5*23 6*75 



Carbonic acid produced . 5*30 5*91 7*87 



Water produced . . . 1-84 1*96 2-80 



Hence in 100 parts, — 



I. II. III. 



Carbon . . 30-30 30*82 31-79 



Hydrogen . 4-28 4-16 4*60 



In the determination of nitrogen by the differential method 

 the proportions of the gases obtained were, — 



I. II. III. 



Carbonic acid . 70-7 53-4 53-8 

 Nitrogen . . . 10*6 6*9 8-0 



These are in the proportion of — 



I. 

 Carbon . . 24-0 

 Nitrogen . . 3*59 



These numbers suggest the simple substitution product 



{HI 

 3 NO I ^20' ^"^ which the per-centage of carbon would 



be 31-37, and of hydrogen 3*70 ; yet the amount of nitrogen 

 is somewhat too great, and there is far from being sufficient 

 evidence to prove the definiteness of the substance itself. 

 The Avide difference also in the results obtained by various 

 chemists can scarcely be accounted for, except upon the sup- 

 position that they have operated upon very different sub- 

 stances. 



The solubility of xyloidine in nitric acid led me to examine 

 whether any alteration could be effected upon pyroxyline by 

 similar means. The most dilute acid which I found to have 

 any effect upon it in the cold was that of sp. gr. 1*414 ; but 

 the alteration took place by means of this only after long 

 standing, and but to a slight extent. Nitric acid of sp. gr. 

 1*45 how- ever is capable of dissolving pyroxyline, and alters 

 both its composition and properties, as will be presently de- 

 scribed ; whilst fuming nitric acid has not the slightest effect 

 upon it. The new product just mentioned is acted upon 

 somewhat differently by various solvents, according to whe- 

 ther it exists in a fibrous condition, or in powder as precipi- 

 tated from solution ; yet I have found by experiment that no 

 alteration in weight is effected by this change of condition. 

 When in fibre it is slightly soluble in strong alcohol, aether, a 

 mixture of aether with one-tenth part of alcohol, and acetic 

 aether ; but when in the pulverulent state it is very soluble 

 in these menstrua, and in glacial acetic acid. In either con- 



