GO 75 BOTANICAL GAZEITE [FEBRUARY 
water transpired in experiments where the salts had a slight influence 
upon growth and also in experiments where influence was large. 1 
selected for this purpose two classes of results, in one of which the 
effect of the added salt upon the green weight of the plants was so small 
as to be doubtful, and in the other there was a distinct acceleration. 
In the first class of results the response as measured by green weight 
varied between 95 and 105, and is regarded as doubtful response, 
since a variation of only 5 per cent. above or below the controls may 
be regarded as within the limit of error. In the other class of results 
the response was 120 or greater, and therefore includes cases in which 
there was undoubted acceleration. 
A summary of the results of these tests is presented in tableI. Each 
computation is the average of 25 tests, with the exception of no. 1, 
which is the average of 20 tests. 
TABLE I 
EFFECT OF VARIOUS SALTS UPON TRANSPIRATION OF WHEAT PLANTS IN 
CASES WHERE THE CORRELATED EFFECT UPON THE GROWTH WAS 
VERY SMALL AND IN CASES WHERE IT WAS DISTINCTLY 
INCREASED. SALTS ADDED TO SOIL IN 
WHICH PLANTS GREW 
Green weight = plants been pcg al 
grown in sous receiv- Z : vf 
No. Salts added ing the salt. Controls ee — 
=TIo00 in each case cake 
I NaNO, 100. 25 95-3 
2 a lee 130.00 84.0 
3 K,SO, 101.00 94.0 
4 ‘2 128.00 86.0 
5 CaH,(PO,), too. 16 100.4 
6 o 128.00 95-5 
7 CaCO, 100.5 99:9 
8 = 142.0 99.0 
These results may be regardéd as giving added light to those 
previously presented. They show that in the case of NaNO, and 
K,SO, there was greater economy of water used the greater the effect 
upon growth as indicated by the green weight. In the case of 
CaH,(PO,), and CaCO,, it has already been shown that their inhibit- 
ing effect upon transpiration is much inferior to that of NaNO; 
