~ 24 FOUNDATIONS OF BOTANY 
-EXPERIMENT XI! 
‘ Testing Brazil-Nuts for Plant-Foods. — Crack fifteen or twenty 
Brazil-nuts, peel off the brown coating from the kernel of each, and 
then grind the kernels to a pulp in a mortar. Shake up this pulp 
with ether, pour upon a paper filter, and wash with ether until the 
washings when evaporated are nearly free from oil. The funnel 
containing the filter should be kept covered as much as possible 
until the washing is finished. Evaporate the filtrate to procure the 
oil, which may afterwards be kept in a glass-stoppered bottle. Dry 
the powder which remains on the filter and keep it in a wide-, 
mouthed bottle. Test portions of this powder for proteids and for 
starch. Explain the results obtained. 
- 31. Other Constituents of Seeds. — Besides the substances 
above suggested, others occur in different seeds. Some 
of these are of use in feeding the seedling, others are of 
value in protecting the seed itself from being eaten by 
animals or in rendering it less lable to decay. In such 
seeds as that of the nutmeg, the essential oil which gives 
it its characteristic flavor probably makes it unpalatable 
to animals and at the same time preserves it from decay. 
Date seeds are so hard and tough that they cannot be 
eaten and do not readily decay. Lemon, orange, horse- 
chestnut and buckeye seeds are too bitter to be eaten, and 
the seeds of the apple, cherry, peach, and plum are some- 
what bitter. 
The seeds of larkspur, thorn-apple,! croton, the castor- 
oil plant, nux vomica, and many other kinds of plants 
contain active poisons. 
1 Datura, commonly called ‘‘ Jimpson weed.” 
