132 On the Conversion of Animal Matter into 



on this sugar. It is less fusible than cane-sugar, and better re- 

 sists decomposition in a raised temperature. By distillation, it 

 gives a light white sublimate, and an ammoniacal product, which 

 shows the presence of azote. This saccharine matter seems on 

 the first view to have some analogy with sugar of milk ; but the 

 latter (as M. Vogel has observed) is changed by sulphuric acid 

 into a sugar very soluble in water and in alcohol ; and besides, 

 the sugar of gelatine, when treated by nitric acid, gives no mu- 

 cous acid, but a new species of acid, which I have named the 

 nitro-saccharine, and will be described in the following para- 

 graph. 



Of the Niiro- Saccharine Acid. 



If nitric acid be poured on suf»ar of gelatine while still co- 

 -Inuved, it does not appear to dissolve in the cold, but becomes 

 very white, and the acid appears to take up the colouring mat- 

 ter : if this mixture be then heated, a solution takes place, but 

 without the evolution of red nitrous vapour, and the effervescence 

 that occurs vvhen other animal and vegetable matters are heated 

 with this acid. This nitrous solution being now evaporated 

 (slowly towards the end), gives a residue which congeals on cool- 

 ing into a single crvstalline mass. This, when pressed between 

 paper and re-dissolved, yields the nitro-sacchwine acid in purity. 

 The c]uantitv of this acid is much more than that of the saccha- 

 rine acid from which it is obtained. It is very soluble, and 

 crystallises with the greatest ease in beautiful, colourless, trans- 

 parent, flattened prisms, slightly striated like Glauber's salt. Its 

 acid and somewhat saccharine taste resembles that of the acid of 

 tartar. When heated by itself, it puffs up considerably, melts 

 indi-'tinctlv, and gives out a pungent vapour. It produces no 

 change on earthy or mctaUic solutions. With potash, it forms a 

 super-acid and a neutral salt, both of which crystallise in fine 

 needles, and have a cooling nitrous taste leaving an after-flavour 

 of sugar. When thrown on hot coals they detonate like salt- 

 petre. The nitro-saccharine acid dissolves carbonate of lime 

 M'ith strong effervescence, and the liquor, gently evaporated, en- 

 tirely passes into fine needled prismatic crystals, which do not 

 deliquesce in the open air, are little soluble in concentrated al- 

 cohol, melt on hot coals, and then detonate. This acid forms 

 with oxide of copper a crystallisable salt unchangeable in the air: 

 with n^agnesia, a deli(iuescent, uncrystallisable salt, which puffa 

 up excessively when heated, melts, and leaves a brown spongy 

 residue resem.bling a vegetation. With oxide of lead it gives a 

 permanent gummy mass that will not crystallise : with iron and 

 zinc it produces metallic salts, evolving hydrogen during solu^ 

 tion. 



These 



