[ 116 



of potatoe starch, procured a pound and a quarter of 

 crystalline, brown sugar ; which he conceives posses- 

 sed properties intermediate between cane sugar, and 

 grape sugar. 



It is probable that the conversion of starch jnto 

 sugar is effected merely by the attraction of the acid 

 for the elements of sugar ; for various experiments 

 have been made, which prove that the acid is not de- 

 composed, and that no elastic matter is set free ; pro- 

 bably th6 colour of the sugar is owing to the disen- 

 gagement, or new combination of a little carbon, the 

 slight excess of which, as has been just stated, consti- 

 tutes the only difference perceptible by analysis be- 

 tween sugar and starch. 



M. Bouillon la Grange, by slightly roasting starch 

 has rendered it soluble in cold water ; and the solu- 

 tion evaporated afforded a substance, having the 

 characters of mucilage. 



Gluten and albumen differ from the other vege- 

 table products, principally by containing azote. When 

 gluten is kept long in water it undergoes fermenta- 

 tion ; ammonia (which contains its azote) is given off 

 with acetic acid : and a fatty matter, and a substance 

 analogous to woody fibre remain. 



Extract, tannin, and gallic acid, when their solu- 

 tions are long exposed to air, deposit a matter similar 

 to woody fibre ; and the solid substances are render- 

 ed analogous to woody fibre by slight roasting ; and in 

 these cases it is probable that part of their oxygene 

 and hydrogene is separated as water. 



