190 GLUCIC ACID. 



Formation. It appears to be formed by the action 

 of sodium-amalgam on sugar of milk. 



Properties. Large, well-formed, monoclinic crys- 

 tals. Easily soluble in water, but slightly in alcohol ; 

 fusing point, 182 ; like mannite, it gives j8-hexyl iodide 

 with concentrated hydriodic acid. 



Dulcite acetate, C 6 H 8 (O.C 2 IPO) 6 . Is formed, to- 

 gether with the diacetate and other acetyl derivatives, 

 by the action of glacial acetic acid, acetic anhydride, or 

 acetyl chloride on dulcite. Small white crystals, that 

 fuse at 171 ; but slightly soluble even in boiling 

 water, moderately easily soluble in alcohol. 



The following substance is isomeric with mannite 

 aud dulcite : 



SorUte, C 6 H 14 6 . Is contained in the berries of 

 Sorbus acuparia. Small, fine needles, which contain 

 | molecule of water of crystallization, and fuse at 110- 

 111 in an anhydrous condition. Almost insoluble in 

 cold water, soluble in water in all proportions. 



B. MONOBASIC, HEXATOMIC ACIDS, C W H 2W 7 . 



Glucic Acid. 

 OTI 12 7 = C 5 H 6 (OH) 5 .CO.OH. 



Formation. From grape-sugar. The dilute aqueous 

 solution of sugar is saturated with chlorine, the excess 

 of chlorine removed by means of a current of air, 

 silver oxide then added until the acid reaction dis- 

 appears, and the filtrate from silver chloride evaporated, 

 after the removal of the dissolved silver by means of 

 sulphuretted hydrogen. 



Properties. Almost colorless syrup, very easily 

 soluble in water, insoluble in absolute alcohol ; mono- 

 basic acid. 



The calcium salt, (C 6 H n 7 ) 2 Ca + 2H 2 0, and the barium 

 salt, (C 6 H ll 7 ) 2 Ba + 3IPO, crystallize in prisms. _ 



The following acids are isorneric with glucic acid : 



