39 
affect them unpleasantly for a short time, but they would uniformly 
recover, and either proceed again to eat or crawl away to another 
plant. In no case were worms injured unless spray was delivered di- 
rectly upon them. Eating of the plants after they had been sprayed 
did not affect them. These experiments occupied several days and 
were duplicated. 
Tests in small Jars. — This was a duplicate test on Plusia brassicce and 
Pieris rapce. The liquid was applied with a feather and in sufficient 
quantity to moisten the entire body of the worm. In dilutions up to 1 
to 5 it killed both; weaker solutions occasionally killed one or more 
rapce but not brassicce. 
In breeding Cages . — In this test the above was duplicated on larger 
scale. Liquid was applied as spray and until all worms were thoroughly 
drenched. They were placed on parts of a small cabbage-head, so that 
each box very nearly represented an out door experiment and enabled 
me to be much more certain of results obtained. 
Up to 5 dilutions 80 j>er cent, of rapce were destroyed and 10 per cent, 
of brassicce , there not being much difference in the strength of liquid 
as to efficacy. Weaker solutions did little or no injury to either. P. bras- 
sicce was not treated with emulsion at all in the field, but from effect 
on rapce am sure that the conditions were essentially those of outside 
experiments. The amount of drenching with this liquid which bras- 
sicce could stand was certainly remarkable. In previous test jars were 
covered. Liquid in each case was taken from same jar of emulsion. 
I had no trouble in making a good emulsion that was stable in what- 
ever dilutions I chose to use it. 
On Cabbage Plant-louse. 
Wherever used on this insect, even in weakest solutions (1 to 1G), 
the emulsion destroyed all that were touched by it. 
On White Grubs. 
A solution of 1 part emulsion to 4 parts water was used quite ex- 
tensively on the larvae of the May beetle, Lachnosterna fusca . The re- 
sults were far from satisfactory. Where used on the lawn the grubs 
descended 2 or 3 inches and were unharmed. Some few appeared a little 
sick, and occasionally a black spot was observed on some of them, but 
none were destroyed. After conducting this test for twenty days it was 
abandoned. Several boxes were arranged with loose soil and grubs 
placed in these for experiment. Here where they were only lightly 
covered with loose soil the emulsion destroyed nearly every one in 
twenty-four hours. The liquid was sprinkled on in these tests suffi- 
ciently to moisten the surface thoroughly. 
Lime and salt were also tried over the lawn and in boxes. On the 
lawn where they washed through, the grubs immediately descended out 
of reach, Slope were actually killed on the lawn that I could observe. 
