Mason — Preliminary Notes on the Carbohydrates of the Musci. 21 



On distillation of the alcohol the chlorophyll is precipitated, filtered off, 

 and washed. 



The extract is next treated with the minimum amount of basic lead 

 acetate, and a little alumina cream. After the removal and washing of the 

 precipitated gum and tannin, the excess of lead is removed by sodium 

 carbonate. The deleaded filtrate is next concentrated, and made up to the 

 required volume. 



This concentration is a source of the greatest trouble, as it involves a 

 browning of the levulose, which renders the use of the polarimeter out of 

 the question. This concentration, however, is rendered inevitable, firstly by 

 the paucity of the sugar present, and secondly by the necessity of using 

 water for extraction in addition to alcohol. 



Benedict's sodium-citrate method (S. E. Benedict (1)) has been used to 

 make the following analysis of P. commune, collected at midday, August 15th. 

 A weighed quantity of the fresh plant (both leaves and stem) was placed in 

 alcohol, and treated as has been above indicated. The dry weight was 

 obtained separately. The sugars extracted from 16 - 7 g. (dry wt.) were made 

 up to 200 c.c. : — 



50 c.c. were used in the estimation of the hexoses, 



sucrose, 

 „ „ maltose, 



and 50 c.c. were placed aside to be used if required. 



100 c.c. of the original solution were found to reduce 0-697 g. CuO. 



To 50 c.c. made slightly acid to litmus paper, 6 c.c. of yeast invertase 

 were added. At the end of twenty hours' incubation, the sugar solution was 

 neutralized, filtered, and made up to 100 c.c. 



100 c.c. (after correction for change in concentration) now reduced 

 10181 g. CuO. 



The sucrose is calculated from the difference in the amount of CuO 

 reduced before and after inversion. 



10181 -0-6971 = 0-321 g. CuO. 



As 1 gram of sucrose yields 1-052 grams invert sugar, which is capable 



of reducing 2-817 grams CuO, the amount of sucrose in 100 c.c. of the 



0-321 

 original solution is expressed by the fraction = 0-1139 g. 



2'817 



For the estimation of maltose 50 c.c. of the inverted solution are treated 



with 3 c.c. of concentrated hydrochloric acid for three hours on a water-bath; 



it is then neutralized with sodium hydroxide, made up to 100 c.c, and the 



increase in reducing power noted. 



fr<ClENT. PROC. R.D.S., VOL. XV., NO. II, D 



