206 
Theory and Practice of Dipping 
Appendix I. 
A tabulation of the results of Watkins-Pitchford’s experiments, to show 
that the killing effect of the dip on the ticks persists for some days 
after dipping. 
Days since dipping 
No. of clays 
since 
attachment 
of ticks 
1st day 
No. of ticks 
attached 
2nd day 
No. of ticks 
attached 
3rd day 
No. of ticks 
attached 
5th day 
No. of ticks 
attached 
7th day 
No. of ticks 
attached 
-^ Controls 
10th day (not dipped) 
No. of ticks No. of ticks 
attached attached 
12 
19 
22 
28 
21 
26 
8 
i day 
10 
18 
21 
22 
20 
21 
8 
1 „ 
3 
9 
8 
15 
14 
15 
8 
1 }, days 
0 
5 
8 
13 
12 
14 
8 
2 „ 
0 
2 
3 
12 
12 
14 
8 
3 „ 
0 
1 
0 
8 
9 
13 
8 
This table is modified and abridged from the table given by Watkins- 
Pitchford (1911a, p. 54). Two beasts were used for each experiment. 
Appendix II. 
The effect of the addition of various substances to solutions of 
sodium arsenite in averting ‘scalding .’ 
Watkins-Pitchford (1911a) gives the results of his experiments 
with plain solutions of sodium arsenite (p. 31) and with sodium arsenite 
solutions to which other substances have been added (pp. 34-37). In 
order to facilitate a comparison of these results, the following table has 
been compiled from his published results. 
Composition of Dip 
Sodium arsenite 
„ + soap 
„ + glycerine + soap 
+ „ + ,, and paraffin 
emulsion 
No. of sprayings 
before' 
scalding occurred 
4 
4 
4 
0 
-fsoap and paraffin emulsion 11 
Remarks 
In 3 separate trials, no 
‘scalding’ occurred 
after 23, 19 and 10 
sprayings respectively 
It will be observed that in these comparative tests, the fluid was 
applied as a spray, our own experience leads us to believe that a dip 
is less apt to scald than a spray and can, therefore, be used a little 
stronger, but, for all practical purposes, these results apply equally to 
either method of application. 
Watkins-Pitchford tried the addition of glycerine, with the hope 
that it would exert an emollient action tending to reduce the irritating 
