The trees are regularly tapped and the coagulated latex which exudes is collected and worked up into rubber.
The mucins and mucoids belong to this group; they are acid and contain no phosphorus; they give the albumin colour reactions but are not coagulated by heat.
A remarkable change occurs when many albumins are boiled with water, or treated with certain acids, their solubility and general characters being entirely altered, and the fluid becoming coagulated.
It differs from egg-albumin in its specific rotation (-57° to - 64°), and in being slowly coagulated by alcohol and ether.
The globulins are insoluble in water and in dilute acids, but soluble in alkalies and in neutral salt solutions; these solutions are coagulated on boiling.