12 
SHEEP SCAB. 
POTASSIUM SULPHIDE DIP. 
Table Showing Results of Laboratory Experiments. 
Date of Treatment 
Condition 
After i 6 Hours 
Condition 
After 48 Hours 
Strength Used 
Dead 
Alive 
Dead 
Alive 
**November 
I 
13 
o 
Full Strength 
★ ♦November 
I 
3 
7 
10 
0 
Y-i strength 
November 
3 
3 
7 
7 
3 
54 Strength 
November 
4 
8 
2 


Full Strength 
November 
6 
22 
5 
27 
0 
Full Strength 
November 
6 
0 
All 

54 Strength 
November 
II. 
Few 
o 

Full Strength 
November 
15 
5 
5 


Full Strength 
November 
i 6 ... 
7 
2 
9 
0 
Full Strength 
November 
27 
9 
i 6 
.... 
.... 
Full Strength 
The laboratory experiments with this dip were not at all encouraging. 
Experiments upon sheep did much better. 
Only the crystals were used in the laboratory. The “full strength” 
mentioned in the table was in the proportion of one pound of crystals to 
five gallons of water. 
Experiments on Sheep — The crjsitals w-ere used in the propor- 
tion of one pound to five gallons of w^ater, on November 10, to 
dip one sheep with a rather large patch of heavy scab on its 
back. The sheep was dipped but once. The w^eather being rather 
cold the sheep was kept in a barn for a few days. 
A lock of wool was pulled twenty-four hours after the dip- 
ping, on which were found thirty-three mites, and all but one 
seemed dead. The wool at this time was quite wet. 
Forty-eight hours after another lock of wool was examined, 
on w hich I found six apparently dead and six active mites. The 
w ool was still moist on the sheep. 
The sheep was repeatedly examined at intervals of a few’ 
days. The mites soon began to increase rapidly, and by the 1st 
of December the sheep had a bad case of scab again. On Decem- 
ber 12 the sheep was dipped in Zenoleum, one part to 200 of 
water, and showed no signs of scab afterw^ards. 
Experiment repeated November 18. At this time a bunch 
of forty sheep wms di]>ped in a preparation made by Dr. Headden 
as follows: 
Nine pounds of potash lye (caustic soda) w’ere dissolved in 
four gallons of wmter, and then thirty-two pounds of flour of sul- 
phur were added slowly, w’hilc the liquor was kept at boiling 
heat. After boiling one hour, the wdiole was put in the dipping 
vat and diluted to 200 gallons. 
**In these two experiments the wool was put in a g-lass tube before it was 
perfectly dry and so kept moist the whole time, which probably accounts for 
the greater effectiveness of the dip in these than in later experiments. 
