SHEEP SCAB. 
15 
BLA(3K LEAF DIP. 
Table Showing Results of I^aboratory Experiments. 
Date of Treatment 
Condition after 
16 hours 
Condition after 
48 hours 
Condition after 
4 days 
Strength 
Used 
Dead 
Alive 
Dead 
Alive 
Dead 
Alive 
November 2 
6 
I 




November 3 
10 
3 
13 
0 
— 
— 
November 6 
3 
6 
6 
3 
6 
3 
■ ^ 
November 27 
9 
9 
— 
— 
— 
— 
December 12. .. ... .. . . 
12 
3 
— 
— 
— 
— 
November 5 
5 
6 
9 
2 
— 
— 
- 5 0 
November 6 
0 
18 
4 
14 
Few 
Several 

November 5 
6 
13 
14 
5 
.... 
.... 
TOO 
Experiments on Eheep — One sheep with a patch of moderately 
heavy scab, the size of a man’s hand, was dipped with Black Leaf 
Dip, in the proportions of one to forty by measure, on Novem- 
ber 10. 
The sheep was examined twenty-four hours after, and sev- 
eral mites seen crawling about in the wool. The wool was still 
quite wet. Two days after the application a lock of wool was 
pulled, upon which ten living and about an equal number of dead 
mites were found. The living mites seemed rather sluggish. 
November 13, the sheep was examined and only an occa- 
sional living mite could be found. Those found were too large 
to have hatched from eggs since dipping. On November 16, a 
careful search revealed but two mites, and on the 10th I looked 
in vain to find a living mite. The sheep was also carefully 
examined on December 5 and again on the 19th, without my 
finding mites or living scab. 
On February 6 the sheep was noticed rubbing its tail againsi 
a feeding trough, and on examination it was found that there 
was a bad patch of scab covering most of the dorsal surface 
of that organ and two small spots were starting on the rump 
at the roots of the tail. The mites that survived the effect of 
the dip seem to have migrated to the tail and were there over- 
looked in previous examinations. 
Experiment Repeated on a Larger Scale — On November 18, 
three bunches of sheep of forty each were treated with Black 
Leaf Dip in the proportion of one gallon to forty-two gallons of 
water. These bunches were treated again December 1. There 
