Chemical Science. 481 



corrected for pressure, and if necessary for temperature, and the 

 carbonic acid ascertained by the removal and analysis of a portion. 

 No correction is required for moisture, the gas always being used 

 saturated with water. 



Dr. Prout considers the principal alimentary substances as redu- 

 cible to three great classes, the saccharine^ the oily, and the albu- 

 minous ; and his paper relates to the first of these. This, with 

 certain exceptions, includes the substances in which, according, to 

 MM. Gay Lussac and Thenard, the oxygen and hydrogen are in 

 the same proportion as in water. Such substances are principally 

 derived from the vegetable kingdom, and being at the same time 

 alimentary. Dr. Prout uses the terms saccharine principle and 

 vegetable aliment as synonymous. 



The following tables show some.of Dr. Prout' s results with several 

 substances, extreme care having been taken in every case to obtain 

 the bodies pure, and nc\y processes often resorted to for that 

 purpose. 



Sugar. 



Carbon. Water. 



Pure sugar-candy 42.85 57.15 



Impure sugar-candy. 41.5 to 42.5 58.5 to 57,5 



East India sugar-candy 41.9 58.1 



English refined sugar.' 41.5 to 42.5 58.5 to 57.5 



East India refined sugar 42.2 57.8 



Maple sugar 42.1 57.9 



Beet root sugar 42.1 57.9 



East India moist sugar 40.88 59.12 



Sugar of diabetic urine 3(). to 40? 64. to 60 ? 



Sugar of Narbotme honey 36.36 63.63 



Sugar from starch 36.2 63.8 



Amylaceous Principle. 



Carbon. Water. 



Fine wheat starch 37.5 62.5 



dried (i.) 42.8 57.2 



„ highly dried (ii.). . 44 56 



Arrow root 36.4 63.6 



dried (iii.) 42.8 57.2 



„ highly dried (iv.) 44.4 55.6 



(i.) Dried between 200^ and 212® for twenty hours, lost 12.5 

 per cent. 



(ii.) Part of the former, dried between 300° and 350° for six 

 hours, lost 2.3 per cent. 



(iii.) Dried as (i.), lost 15 percent. 



(iv.) Part of the last, heated to 212° for six hours longer, lost 

 3.2 per cent. more. 



LiQNiN, or Woody Fibre, 

 Obtained by rasping wood, and then pulverising it in a mortar ; 

 boiling the impalpable powder in water till nothing more was 



