4o8 Cofnparatlve Analyfes of Gums and Sugar, 



for the charcoal, which was of a beautifully black colour, burned out completely when ex» 



pofed to a ftrong red heat. 



Being defirous of afcertaining more completely the difference between common fugar 



and the faccharine matter fecreted by the breads of animals, an ounce of the crydalhzed 



fugar of milk was diftilled in an apparatus fimilar to that already defcribed, and the pro- 



du(fls were found to be, 



oz. dr. gr. 



Pyromucous acid, mixed with a very little empyreumatic oil, 060 



Charcoal, with a little phofphate of lime, - - 010 



Carbonic acid gas, - - - - 31 oz. meaf. 



Hydro-carbonate, of the fame nature with that obtained in 



the former experiments, - _ _ 103 ditto. 



The charcoal being burned in an open crucible, there remained about one grain, which 

 appeared to be phofphate of lime chiefly. 



The pyromucous acid was next fuperfaturated with lime ; but the quantity of ammonia 

 difengaged was fo fmali that it could with difficulty be detected: there appeared, however, 

 to be a very little. 



Hence, then, it would feem that this animal fugar, contrary to what might be expefted, 

 contains hardly any azote. 



It would appear alfo, that it contains lefs charcoal, and more oxygen, than common 

 fugar. 



In order to invefligate ftilj further the nature of thefe fubflances, we endeavoured to- 

 afcertain the quantity of oxalic bafis or radical contained in each, or how much oxalic acid 

 they would afford when treated with an equal proportion of the nitrous acid. 



An ounce of fugar was added to fix ounces of the concentrated nitrous acid, diluted with 

 an equal bulk of water. When the adlion had in a great meafure ceafed, heat was applied, 

 and the evaporation continued until the liquor was reduced to about an ounce by mea- 

 fure : after this had cooled, the cryftals were feparated by fdtration, and the remaining 

 fluid again evaporated, until the whole, when cold, fliot into a mafs of cryftals, leaving 

 only a few drops which refufed to cryftallize. Thefe cryftals being colle<n:ed, and well dried 

 on blotting paper, amounted to 4 dr. 20 gr. or a little better than half the weight of the 

 fugar employed. 



An ounce of gum arable was next treated with an equal proportion of nitrous acid pro- 

 perly diluted : the quantity of cryftals colleded amounted to J dr. 36 gr.; but in this in- 

 ftance, the laft cryftals obtained were mixed with an infoluble white powder, which, being 

 feparated from the oxalic acid by the addition of diftilled water, amounted to 6 gr. and 

 was found to be oxalate of lime. The pure acid, therefore, did not exceed 3 dr. and a. 

 half. An equal quantity of gum tragacanth afforded, by the fame procefs, 3 dr. 10 gr. 

 of oxalic acid, and 10 gr. oxalate of lime. 



An ounce of the fugar of milk was alfo treated in a fimilar manner, with fix ounces of 

 the concentrated nitrous acid properly diluted, and there were obtained in all 3 dr. 48 gr» 

 Thefe cryftals, however, were mixed with a white powder, which, being but a little fo- 

 luble in water, was readily feparated : it amounted to 30 gr. and appeared to be the fac- 

 eholai^ic acid of Scheeici hence the pure oxalic acid did not exceed 3 dr, 18 gr. 



