The trees are regularly tapped and the coagulated latex which exudes is collected and worked up into rubber.
Albumins (as classified above) are soluble in water, dilute acids and alkalies, and in saturated neutral salt solutions; they are coagulated by heat.
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.
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.
In general they resemble coagulated albumin, and also the gelatin-yielding tissues, but they themselves do not yield gelatin.
RUBBER, INDIARUBBER or Caoutchouc (a word probably derived from Cahucha or Gaucho the names in Ecuador and Peru respectively for rubber or the tree producing it), the chief constituent of the coagulated milky juice or latex furnished by a number of different trees, shrubs and vines.
The latex, which is usually coagulated by standing or by heating, is obtained from incisions in the bark of the tree.
The creosote and other products from the smoke no doubt act antiseptically and prevent to a large extent the subsequent putrefaction of the proteids retained by the coagulated rubber.
It is then coagulated by the addition of an acid liquid, acetic acid or lime juice being generally employed, and the mixture allowed to stand.
The coagulated rubber separates as a mass of spongy caoutchouc. If the coagulation has been effected in shallow dishes, the rubber is obtained in a thin cake of similar shape known as a " biscuit."
The coagulated rubber separated from the watery fluid is cut up into small pieces and passed through the grooved rollers of the washing machine, from which it issues in sheets, long crinkled ribbons or " crepe," which are then dried in hot air chambers or in a vacuum dryer, by which means the water is dissipated at a lower temperature.
In order to prevent decomposition of any proteid impurity which may remain incorporated with the rubber, the freshly coagulated rubber is sometimes cured in the smoke of burning wood or a small quantity of an antiseptic such as creosote is added during coagulation.
Milk, which is acid, is coagulated by 1, leaf; 2, twig with the addition of the alkaline juice of male flowers; 3, twig the ' ` achete " plant, or of another with female flowers; plant called " coasso."
When coagulated in water, the mass is placed in vats in the ground and allowed to dry, this taking place in about a fortnight.
The Funtumia latex can also be coagulated by the astringent infusion of Bauhinia leaves or by exposing it in shallow dishes, when the liquid " creams."
Pernambuco rubber, as is the case with most rubbers coagulated by saline solutions, contains a large quantity of water.
The boiling juice is run down into subsiding tanks, where it cools, and at the same time the albumen, which has been suddenly coagulated by momentary exposure to high temperature, falls to the bottom of the tank, carrying with it the vegetable and other matters which were in suspension in the juice.
The Hevea product is obtained annually by tapping the trees and coagulating the sap over a smoky fire, but the caucho is procured by felling the tree and collecting the sap in a hollow in the ground where it is coagulated by stirring in a mixture of soap and the juice of a plant called vetilla.
Both these soluble hydrates are readily coagulated by traces of a salt, acid or alkali; Crum's hydrate does not combine with dye-stuffs, neither is it soluble in excess of acid, while Graham's compound readily forms lakes, and readily dissolves when coagulated in acids.
A bubo is found to consist of a chain of enlarged glands, surrounded by a mass of engorged connective tissue, coagulated blood and serum.