February, ’18] HARTZELL: MOLASSES AND ADHESIVENESS 
65 
Table Giving Data op Adhesive Tests 
Material Applied to Plates 
Average Amount of 
Material on Plates after 
Drying 24 Hours and 
before Sprinkling, 
Grams 
Average Amount of 
Material on Plates after 
Sprinkling and Later 
Drying for 24 Hours, 
• Grams 
Per cent of Mate¬ 
rial Remaining 
on Plates 
Number 
of Plates 
Used 
Brand A, a paste arsenate of lead 
without molasses. 
.0587 
.0017 
2.9 
5 
Brand A with molasses. 
.2632 
.0012 
*2.0 
5 
Brand B, a paste arsenate of lead 
without molasses. 
.0424 
.0024 
5.7 
5 
Brand B with molasses. 
.1452 
.0002 
* .5 
5 
Brand C, a paste arsenate of lead 
without molasses. 
.0580 
.0509 
87.8 
5 
Brand C with molasses. 
.1611 
.0158 
*27.2 
5 
Brand D, a paste arsenate of lead 
without molasses. 
.0353 
.0140 
39.6 
3 
Brand D with molasses. 
.1426 
.0046 
*13.0 
3 
Brand E, a dry arsenate of lead 
without molasses. 
.0479 
.0039 
8.1 
2 
Brand E with molasses. 
.1814 
.0047 
*9.8 
2 
Brand F, a dry arsenate of lead 
without molasses. 
.0707 
.0079 
11.2 
2 
Brand F with molasses.. 
.2070 
.0045 
*6.4 
2 
Brand G, a paste arsenate of lead 
without sugar. 
.0546 
.0089 
16.3 
3 
Brand G with cane sugar. 
.1564 
.0016 
*2.9 
2 
Brand H, a commercial preparation 
of Bordeaux and lead without 
molasses. 
.0501 
.0438 
87.4 
5 
Brand H with molasses. 
.1840 
.0016 
*3.2 
5 
*In the tests in which molasses was added we have assumed that the same amount of insecticide was added that was 
found on the plate of the same brand without molasses and have calculated the percentage retained using this 
amount as the base. 
brands of leads; (2) no dry arsenate of lead proved as adhesive as the 
better adhering paste arsenate of leads; (3) several of the brands of 
paste arsenate of lead had poorer adhesive qualities than the brands 
of dry arsenate of lead tested; (4) in every instance, save one, the 
addition of molasses to an arsenate of lead lessened its adhesive 
properties and this decrease in sticking power was greater in some 
brands than in others; (5) molasses greatly decreased the adhesiveness 
of a commercial preparation of Bordeaux mixture and arsenate of 
lead; and (6) cane sugar used in practically the same amount as con¬ 
tained in molasses caused marked lack of adhesiveness in arsenate of 
lead and therefore we believe that the sugar contained in the molasses 
is largely responsible for the decreased power of adhesion. 
The results just given are of a preliminary nature and further 
investigation of this problem is planned. However, it is worthy of 
note that when the same combinations were tested on grape foliage 
during the period from 1913 to 1916 it was found that any brand of 
arsenate of lead which showed poor adhesiveness in the laboratory 
tests also proved to adhere poorly to grape foliage. It was not pos¬ 
sible, however, to determine these variations on the leaves with as 
high a degree of precision as in the laboratory. 
Having determined the above facts we were able to secure excellent 
results with molasses and arsenate of lead for the control of the grape 
6 
