72 BOTANICAL GAZETTE [JANUARY 
labels, except those for identification, are necessary on the separate 
batches of material; and the series of alcohols and xylols may be used 
repeatedly, for while there is a continual weakening of each grade in the 
series, the weakening is proportional throughout the whole series, so that 
their relation to each other remains practically unchanged.—WINFIELD 
DupcEon, Ewing Christian College, Allahabad, India. 
THE RELATION BETWEEN THE TRANSPIRATION STREAM 
AND THE ABSORPTION OF SALTS 
During the winter of 1908-1909 experiments were conducted at 
Santiago de las Vegas, Cuba, in order to determine the comparative 
transpiration of tobacco plants under cheesecloth shade and in the open 
ground. For this purpose plants were grown in galvanized iron tanks 
which were set into outer incasing tanks permanently sunk in the ground. 
Six tanks were placed among the plants of a field of tobacco grown under 
cheesecloth, and six were set in an adjoining tobacco field not shaded. 
The quantity of water transpired by the plants in the tanks was deter- 
mined by daily weighings, the quantity transpired being replaced each 
day. At maturity the leaves, stems, and roots of each plant were 
harvested separately, dried, and ground. The ash was determined in 
water-free samples of the ground material. From the data the total ash 
of the plants was calculated. The condensed results of the experiment 
are given in the following table. 
PLANTS GROWN IN THE OPEN 
No. of plant ‘substance pro spiel water, | Total ash in. | Water abecrbet 
te es 209.03 52,006 18.19 oe 
cE pi ss GE 168. 33 42,059 16.74 2512 
6 eA ae IQI.OL 46,840 20.54 Seinen 
O° : ee ea. 187.97 45,418 16.74 Se 
Wiel ea 185.06 46,447 18.86 a 
Eee nmr par nase 188.20 45,234 Fs we 
Average........ 188.42 46,344 18.25 2548 
