AGRICULTURE AND PLANTING. 21 



On the component Principles of' Vegetables. 



oi wheat, potatoe, sago, salop, briony, and cassava. #• 



VII. Concerning the Vegetable GtUTEN. 



The glutinous principle, Avhich, on account of its properties resembling 

 those of animal substances, has been called the vegeto -animal substance by some 

 chemists, is more particularly obtained from gramineous vegetables. In grains, 

 it co-exists with foeculum, and saccharine substance. JFIieat appears to con- 

 tain it in a greater proportion than most other grains. It exists in the best flour; 

 in proportion of — from ^ fifth to a third part. Because X)f its contahiing this mat- 

 ter in such a proportion, the flour of wheat is more Avholesome and nutritious, 

 as an article of food, than oats, potatoes, or any other farinaceous substance. 



VIII. Concerning Sugar, 



The saccharine principle is detected by the taste in many vegetables, especi- 

 ally in dates, figs, siliquce dulces, cassia in the pod; raisins^ apples, quinces, plums, 

 cherries, mulberries, currants, &c. but the plant in which it exists in the greatest 

 quantity, and from which it is obtained for economical purposes, is the arundo 

 saccharifera, or sugar cane, which is bruised between iron cylinders in the west 

 and east Indies, where it is cultivated; the juice, called Melasses, is then express- 

 ed, and by several operations made into sugar. The trunks of the acer saccha- 

 rifera and fraxinus ornus also affbrd this principle very largely; as is evident 

 from the quantity of manna, which spontaneously flows every season froih their 

 barks. It may likewise be obtained from carrots, parsnips, the roots of dan- 

 delion, ferns, liquorice, &c> 



Great god of justice and wisdom! grant that this luxury may in thy 

 good time be cultivated by.the hands of Freemen; and may thence give happiness 

 to the labourer, as well tis to the merchant and consumer. 



IX. Concerning the Vegetable Acids. 



i - 



The vegetable acids have been long considered to be weaker than the others ;- 

 and this opinion was adhered to until it was observed that the oxalic acid sei^d 



