sept. 2,1918 Comparative Toxicity of Cottonseed Products 
433 
Table 1 — Effects of various diets on the growth of rats — Continued 
unsupplemented diets— continued 
2 
£ 
Average 
*3 
weight. 
S 
Diet. 
Change. 
Duration of experiment. 
I 
Ini¬ 
tial. 
Final. 
Gm. 
Gm. 
P. cl. 
2 
Cold-pressed meal 
148 
152 
+ 3 
Discontinued after 
from mill W, 50 
per cent. 
15 days. 
2 
Hot pressed meal 
126 
109 
-13 
Discontinued after 
from mill T, 50 
per cent. 
14 days. 
3 
Ether extract of 
143 
116 
-17 
Discontinued after 
above 12.5 per 
10 days. 
cent, with milk 
powder. 
3 
Soybean meal, 70 
45 
51 
+ 13 
Discontinued after 
per cent; lard, 3^ 
per cent. 
79 days. Failure. 
3 
Soybean meal, 25 
46 
47 
— 2 
Discontinued after 
per cent; com 
30-40 days. Fail- 
meal, 75 per cent. 
ure. 
3 
Cottonseed meal, 25 
46 
37 
—20 
Discontinued after 
per cent; com 
meal, 7 5 per cent. 
50 days. Failure. 
Period 1: Cotton- 
67 
79 
+18 
Discontinued after 
■3 
seed flour, 30 per 
cent; com meal, 
68 days. Stopped 
growing entirely. 
O 
42 per cent; lard, 
28 per cent. 
Period 2: Ether-ex- 
79 
106 
+34 
Discontinued after 
tracted cottonseed 
68 days; better 
kernels in place 
of cottonseed flour 
growth than dur¬ 
ing period 1. 
i 
l (fig- 3 -) 
Experiment and 
diet No. 
Experiment 5- 
Continued. 
45i. 
a 460. 
460A. 
Experiment 6: 
380.. 
381. 
375 - 
383- 
3 8 3A. 
0 The meal in diet 460 contained some unchanged gossypol. 
In experiment i the rats on the extracted kernels made fair progress 
until failure set in after 140 days. Rats on soybean meal failed after 
128 days. These diets contained 50 per cent of the food under experi¬ 
ment, together with 22 per cent of starch and 20 per cent of lard. 
In attempts to find a cottonseed meal which would be markedly toxic 
to rats, even in milk-powder diets, we fed several samples of so-called 
cold-pressed meal. Here, also, we failed to find marked toxicity. This 
was puzzling at the time, but investigation showed that in the so-called 
cold-pressing a large amount of the gossypol passes into the crude oil, 
which is highly toxic, and the remainder is more or less changed, so that 
there is nothing inconsistent in these results. It may be mentioned 
that by actually using cold pressure on raw cottonseed kernels, Osborne 
and Mendel obtained an oil which was not appreciably toxic, though the 
