Intelligence and Miscellaneous Articles. 237 



ON SUGARS. BY M. PELIGOT.* 



Common Sugar. — On repeating the analysis with all possible care, 

 the author found that the formula long since adopted is that which 

 best agrees with experiment : this formula is C'-^ H'^'^ O " f. 



M. Berzelius found that the compound of sugar with oxide of lead, 

 is C'^* H-o O '0, 2 Pb O. On drying this salt at 320° Fahr., M. Peligot 

 obtained C'-^ H's O^, 2 PbO. Anhydrous sugar will therefore be C^* 

 His O" instead of C^* W Oi". 



The author also obtained a crystallized saccharate of barytes, 

 crystallized by the direct contact of sugar and barytes dissolved in 

 water, and he found the formula to be C-* H— O", BaO ; he com- 

 bined sugar with common salt, and found the composition of this 

 body to be C+« H^"- O^', Ch"- Na. 



Sugar of Starch and of Diabetes. — The formula of these and of 

 the grape and honey sugar, M. Peligot found to be C-^ H-^ O'*. He 

 also analysed the compound of diabetic sugar and common salt 

 obtained by Calloud, and found that this curious product is repre- 

 sented by the formula C"**^ H^- O"^, Ch- Na ; the compound of sugar 

 of starch and oxide of lead, obtained by the contact of ammoniacal 

 acetate of lead and sugar dissolved in excess, was found to be C''^ H^'^ 

 O^, 6 PbO ; the saccharate of barytes from sugar of starch is repre- 

 sented by C« Ho6 028, 3 BaO. 



M. Peligot found that common sugar is the only one which com- 

 bines with the alkalis without suffering change. Sugar of starch 

 and all other known sugars, at first combine with the alkalis, and 

 are gradually destroyed, giving rise to two distinct products, ac- 

 cording to the circumstances of the mixture of these bodies. 



Lime dissolved in a solution of starch sugar, gradually loses its 

 caustic property, and is saturated by an acid formed by its influence. 

 The salt of lime formed, when rendered neutral, is abundantly pre- 

 cipitated by subacetate of lead. The formula of the insoluble salt is 

 C48 1130 015, 6 PbO. The disengaged acid could not be conveniently 

 examined : it is not volatile, and forms salts, almost all of which 

 are soluble in water. On heating the solution of starch sugar and 

 an alkali, a more rapid action is observable ; the mixture becomes 

 coloured, and a brownish-black acid is formed, having some resem- 

 blance to ulmic acid, but it is quite distinct from it. Its composition 

 is represented by the formula C^s H^oQ'o. It appears to be iden- 

 tical with the acid obtained by M.Suanberg, in treating the acid of 

 catechu with caustic potash, which has the composition represent- 

 ed by the preceding formula ; nevertheless differences occur in the 

 analyses, which indicated one per cent, too much hydrogen. This 

 acid is very readily obtained with fused starch sugar, and a concen- 

 trated solution of potash ; the action is rapid. When the colour has 

 become very intense, water is added, and the acid is precipitated by 

 hydrochloric acid. If it be identical with the japonic acid, this 

 acid is represented by C^^^H'^ O^, These two acids differ from sugar 



• See Prof. Graham's paper, p. 219. of the present number.— Edit. 

 f The original atomic weights are preserved. 



