44 SUGAR CONTENT OF MAIZE STALKS. 



of stalk-borers. The results were, however, interesting in that 

 they afforded data in regard to the sugar content of stalks so 

 infested. 



During the season just completed, a more extensive series 

 of experiments has been made for the purpose of investigating 

 the sugar content of stalks of five varieties of maize, four of 

 which are commonly grown in this country. The five varieties 

 under trial were Hickory King, Salisbury White, Boone County, 

 Golden Eagle, and Sweet Corn. 



The ground used for the experiment — a heavy red loam — 

 was well prepared, and kept in good tilth throughout the season. 

 The maize was sown on November 9th, and all varieties making 

 very good growth and being entirely free from insect attack 

 the plants were in every way suitable for the purpose of the 

 investigation. From a portion of each plot, the cobs were 

 removed in a milky condition on April 2nd. and the juice of 

 stalks selected from the cobbed and uncobbed portions analvsed 

 periodically until the crop reached maturity. 



Methods of Analysis Employed. 



One or more stalks of the variety to be examined were 

 selected in the plot, and the juice thereof submitted to analysis 

 on the same day. The " stripped stalk " was weighed, cut into 

 strips not more than half an inch in thickness, and the juice 

 expressed under gradually increased pressure between the steel 

 rollers of an ordinary flattening mill; the juice collected weighe:! 

 and strained through a fine linen cloth. The specific gravity was 

 determined with a *' specific gravity bottle." For the deter- 

 mination of total solids in the strained juice, 5 c.c. were intro- 

 duced into a 2 : h inch aluminium basin, the bottom of which was 

 previously covered with coarse sand to insure complete desicca- 

 tion, evaporated to dryness on a- water-bath, and kept at a 

 temperature of 95°C. until the weight became constant. For 

 the determination of sucrose and glucose. 100 c.c. of the juice 

 were taken and defeated with basic lead acetate and alumina 

 cream. In the hltrate from the lead precipitate, which was 

 perfectlv clear, the sucrose was determined by the polariscope 



* In order to determine if any optically active constituent other than 

 sucrose was present in normal juice, several determinations of the sucrose 

 by cuprous precipitation before and after inversion as well as direct polari- 

 sation were made ; in every case the amount shown by the different methods 

 agreed very closely, indicating that sucrose was the only optically active 

 substance present. 



