Dec. is, 1916 Influence of Bordeaux Mixture on Transpiration 
539 
.to the growth of the plants during the periods after spraying would affect 
approximately alike the green- and dry-weight values of both series A' 
and series B. If, in the treatment of these ratios the green-weight 
values for series A and for series A' (the values for these two series being 
the same) are denoted by “ G,” and the corresponding values for series B 
are denoted by * *G',” it follows that the ratios of A to G, A' to G, and B to G' 
must represent the water loss per gram of green substance for series A, 
series A', and series B, respectively. Now, the ratio between the average 
water loss per gram of green substance for series A and for series B 
A*G AG' 
(periods before spraying) is expressed by g-^,,or The correspond¬ 
ing ratio value between the average water loss per gram of green sub¬ 
stance for series A' and for series B (periods after spraying) is expressed 
by 
A':G 
B:G ,J 
or 
A'G' 
BG * 
If, therefore, the ratio of AG' to BG is less than that 
of A'G' to BG, the water loss per gram of green substance must be greater 
for the sprayed plants than for the unsprayed. 
The dry-weight values for series A' and for series B will be denoted 
by “D” and “D',” respectively, and the ratios between the water loss 
per gram of dry substance for periods before spraying and the corre¬ 
sponding ratio for periods after spraying, derived in the same manner 
as the ratios between the water loss per gram of green substance, are 
expressed by the ratios of AD' to BD and A'D' to BD, for standardiza¬ 
tion periods and for periods after spraying, respectively. 
CABBAGE PLANTS 
In this experiment the plants used were vigorous and fairly uniform 
in size. The standardization period continued from March 1 to March 4. 
The period after spraying began on March 4 and continued to March 17. 
Considerable difficulty was encountered in attempts to spray the 
leaves of the cabbage plants. The bloom on the surface of the leaves 
prevented the spray material from adhering. Various substances were 
added to the spray material in an attempt to find something which 
would cause the spray to adhere to the leaves. Rosin-fish-oil soap in 
the proportion of 2 pounds to 50 gallons of Bordeaux mixture, as rec¬ 
ommended by Hawkins (10), proved to be the most effective; but even 
this did not give the desired results. It was found that by lightly brush¬ 
ing the surface of the leaves with a wad of dry absorbent cotton, and by 
immediately afterwards applying the spray, a surface film of the spray 
could be obtained. This film was by no means ideal, but it was better than 
that secured by using the rosin-fish-oil soap in connection with the Bor¬ 
deaux mixture. The leaves of the control series B were also lightly 
brushed with a wad of absorbent cotton at the same time that the leaves 
of series A' were thus treated. Only the upper surfaces of the leaves 
were thus treated and sprayed. 
