24 FOUNDATIONS OF BOTANY 



EXPERTMENT XI 



Testing Brazil-Nuts for Plant-Foods. — Crack fifteen or twenty 

 Brazil-nuts, peel ofE 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 liable 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, thom-apple,i croton, the castor- 

 oil plant, nux vomica, and many other kinds of plants 

 contain active poisons. 



1 Datura, commonly called " Jimpson weed." 



