GUM IN PLANTS.

Otago Witness, Issue 1248, 30 October 1875, Page 18

GUM IN PLANTS.

It will be strange to those who have noticed what is generally termed gumming in some varieties of fruit trees— such as the Cherry, the Peach, and the Plum— to be told that gum is a compound substance of plants. It exists in variety, some sorts being insoluble in water — Cherry-gum, to the best of our recollection, being of this nature ; other varieties of gum are readily soluble in water. Gum is a combination of carbon and x>xygen — rather more of the latter than of the furmer — with a small proportion of hydrogen. Starch is found in large quantities in several very common plants, particularly Barley, Wheat, Peas, Potatoes, &c, and consists of carbon, oxygen, and hydrogen — the half of the whole being oxygen. In Harley it exists to a great amount, rather more than 80 per cent. ; in Wheat about 70 per cent. ; Peas 45 per cent.' ; and Potatoes 15 to 20 per cent., according to quality. Then, again, the element or compound termed sugar, so largely pre-ent in fruits, and some trees and roots, is very similar in its composition to that of starch. That obtained from the sugar-cane has more of carbon and less oi oxygen in it than that of grape and most other sugars. — The Gardener.