w. NiCOLl. 
179 
to develop more rapidly and normally and by the twelfth to the 
fourteenth day they were fully grown (0-56-0-63 mm. in length) although 
even then a large number of them did not appear to be ensheathed. 
The mortality amongst these larvae was greater than normal although 
not by any means excessive. 
This retardation of the development in cultures from 3 and 4 can 
only be attributed, so far as I can see, to the effect of the salt on the 
eggs. It occurred to me that perhaps the effect was due to the salt 
not having been thoroughly washed out in the cultures, but on making 
accurate estimations it was found that the amount of salt in the culture 
fluid was only 0-018-0-046 %. 
The results of this experiment may be tabulated as follows: 
Experiment started \?>th April, 1914. 
April 
Weight of 
Weight 
Percentage 
-- 
-’ 
20 
-S, 
faeces 
of salt 
of salt 
14 
lb 
16 
17 
18 19 
21 
1. 
2-1 g. 
0-40 g. 
19% 
2. 
4-1 g. 
0-41 g. 
10% 
3. 
4-3 g. 
0-21 g. 
5% 
+ 
+ 
-t- 
- 
+ - 
- 
- 
4. 
3-9g. 
0-10 g. 
2-5 % 
+ 
+ 
-1- 
+ 
+ 
- 
- 
5. 
Control 
+ 
+ 
+ 
+ 
+ + 
+ 
+ 
This experiment appears to show that under favourable circum¬ 
stances and with thorough admixture of salt even 10 % will efiectively 
kill all the eggs within 24 hours, but that 5 % is not sufficient to kill 
fhem in less than five days and is in this respect not much more efficient- 
than %. 
V. This series is chiefly remarkable for the fact that it was con¬ 
ducted with faeces which, as appeared after treatment, contained only 
eggs of Necator americanus. The faecal material was fairly solid but 
rather moist on the surface. The weights of faeces and salt employed 
were as follows: 
Weight of 
faeces 
Weight of 
s^t 
Percentage 
of salt 
1. 
2-2.2 g. 
0-18 g. 
8-1 % 
2. 
1-94 
0-12 
6-2 % 
3. 
2-13 
0-08 
3-8 % 
4. 
2-85 
0-06 
2-1 % 
6. 
2-50 
— 
Control 
As in the previous experiment the salt was thoroughly mixed with 
the faeces and the technique was the same throughout. Particular 
