RED-SQUILL POWDERS AS RATICIDES 
9 
As the results of these prehminary experiments indicated that 
squill is of value as a rat poison, the investigational work was con- 
tinued, material from a second shipment of approximately a ton of 
squill bulbs from Sardinia being used. Upon reaching the United 
States in the fall of 1925, the 200-pound bags of squill were stored 
at 4° to 5° C. Samples were drawn from time to time for the prepara- 
tion of powders. 
Essentially tbe same method of preparation was used as in the 
preliminary experiments. As previous investigation had indicated 
the desirability of using high temperatures in order to check fer- 
mentation or enzyme action quickly, an electric oven that could be 
set to within 1° was used for drying most of the powders in this 
series. In some instances it was desirable to dupHcate commercial 
conditions. For such drying a commercial steam drier was used. 
Dried material was ground to pass through a 40-mesh sieve and packed 
in jars. The approximately }{-inch-thick slices obtained in the com- 
mercial runs by using a hand-operated slicing machine proved to be 
too thin, as a large quantity of mucilaginous juice was exuded, facil- 
itating fermentation and materially retarding drjdng. Shoes half an 
inch thick were found to be more satisfactory. 
By using the method finally adopted for the preparation of squill 
powders (p. 33), it has been possible to reproduce powders having 
the same toxicity. 
METHOD OF FEEDING 
Most of the toxicity determinations were made on w^hite rats. 
Wherever feasible, results on wild (brown) rats were also obtained 
All rats were held in cages for about a week to make the experimental 
animals essentially uniform. No rats weighing less than 100 grams 
each, and when possible only those that weighed between 150 and 
250 grams each, were used. None of the rats received food for 18 
hours, but all were given water freely, to insure a somewhat constant 
appetite and to favor the rapid consumption of the experimental diet. 
As previous experiments had indicated that rats readily consume 
1 per cent of their body weight, efforts w^ere made to feed approxi- 
mately this quantity of total food. 
Animals were weighed and placed in separate cages. The ordinary 
laboratory rat food — 99 per cent of a mixture of whole-milk powder 
(one-third) and w^hole wheat flour (two-thirds) and 1 per cent of salt — 
was passed through a 40-mesh screen. The sample of squill to be fed 
was thoroughly mixed wdth this food, so that approximately 1 per cent 
of the animal's body weight would be fed in gi\TLng the desired dose of 
squiJl. The weighed sqiull-rat-food mixtures were placed in indi\ddual 
glass sponge cups. The time when these cups were placed in the 
cages was noted, and frequent inspections were made to determine 
the time at which all food had been consumed. The dish was then 
removed and the rat left without food and water until the next 
morning. 
Frequent inspections were made to determine the onset of symptoms 
of squill poisoning. Several times the fatal dose of fresh scales or of 
food containing squill powder has been readily eaten. Concentra- 
tions up to 40 per cent of sqmll powder in rat food have been rapidly 
and completely devoured, indicating that the presence of calcium- 
53580°— 29 2 
