- 4 8 



OXIDATION PRODUCTS. 



The gum-enzyme was oxidized by heating I part of gum 

 with 12 parts of nitric acid 1.15 sp. gr. on a water bath for one 

 hour then evaporating to 2 parts and adding water 2 parts. 

 After 24 hours the white crystalline deposit was washed with 

 water and alcohol, and recrystallized from boiling water. The 

 melting point was the same as for Mucic acid 210 C. When 

 analyzed : 



0.222 Gm. gave 0.1085 Gm. H 2 O, 0.2844 Gm., CO 2 . 



Calculated for Mucic acid 



C H 10 Os 

 C .............. 3448% 34-278 



H ............. 4-644 4796 



O ............. 60.926 



100.000 



After removing the mucic acid with hot water from the first 

 crystalline deposit, there remained a white powder insoluble in 

 hot water, alcohol or acetic acid but soluble in hydrochloric acid. 

 This was calcium oxalate which had been formed by the union 

 of the calcium of the gum with the oxalic acid formed by oxida- 

 tion. The mother liquor was evaporated to dryness, washed with 

 ether, which on evaporation left well defined crystals of tartaric 

 acid. 



HYDROLYSIS OF LACGUM. 



The gum-enzyme was heated with 2% sulphuric acid for 

 8 hours and the acid removed with barium hydroxide and carbon- 

 ate. The solution was evaporated under diminished pressure, 

 when it formed a very light yellow syrup, non-crystallizable, non- 

 fermentable, reduced Fehling's solution and was dextrorotary. 

 Alcohol dissolved only a small part of it. The remainder could 

 be dissolved by using a large quantity of hot alcohol but deposited 

 on cooling. 



One part of the syrup was heated one hour with two parts 

 of phenylhydrazine, 3 parts of sodium acetate, and 20 parts of 

 water. On cooling an abundant yellow crystalline deposit formed. 

 This was several times recrystallized from hot alcohol, when the 

 M. P. remained constant beginning at 162 C., and was complete 

 at 164 without liberation of gas. The crystals were in small 

 spheroidal clusters, which under the microscope appeared to con- 



