OF THE ASH-LEAVED MAPLE. 



41 



" run " ceased. Further, it will be noticed that, as regards one of the trees (the male), the 

 two days on which the largest quantities of sap were obteiued were days on which the 

 mean velocity of the wind was low ; but whether there was any real connection between 

 this low velocity and the flow of sap it is impossible to say. 



The sap was clear and limpid, and remained so for several days if allowed to stand in 

 a cool place. On heating, it became slightly turbid from separation of albuminoid sub- 

 stances, or possibly in part from precipitation of calcium phosphate. In general it had a 

 very faint reducing action upon Fehling's solution ; but the reducing action increased 

 slightly during the last few days of the " run." The sugar was estimated daily by means 

 of the polariscope,' and the determinations are recorded in the accompanying Tables (II 

 and III) :— 



Table II. — Negundo aceroides. (Female.) 



From these tables it will be seen that in the case of the female tree the largest pro- 

 portion of sugar was 2.6*7 per cent, on the 6th of the month, the smallest 2.26 per cent. 

 on the 13th. The average for the first seven days was 2.49 per cent., and for the last 

 seven days 2.34 per cent. In the case of the male tree the highest percentage of sugar 



' It is assumed that the rotation is entirely due to cane-sugar. 



^ The quantity of sap necessary to make a pound of crude sugar would be rather less than the figures given in 

 the tables, which represent gallons of sap to make a pound of jmre sugar. 



Sec. iii, 1887. 6, 



