GUM AND ITS USES

New Zealand Tablet, 29 May 1919, Page 39

GUM AND ITS USES

I I i 'i n ...s ■■ t £k"*% . VPJ AH • i One of the strangest of the discoveries of the war is the use of gum-arabic for shell-shock cases. At first sight the two things seem to be wholly unrelated. How can gum be used to cure a man;' suffering from nervous disorders consequent g upon shell-shock ? The answer to. this question is encouraging, while at the ; same time it discloses our great ignorance of the human machine and its action. Every disturbance of the normal rhythm of life is accompanied by some chemical and physical" change within the organism. We notice that a nervous ? shock may .cause the victim to lose weight and gradually waste’ 1 away. £. It has long been known that a number -of diseases., produce some ..change in the circulating fluid in the body. Saline injections have been used ,in numerous cases, and their effect'is not only mildly stimulating, but slightly restores the fluid “balance.” But saline solutions tend to escape into the tissues in much the same way as the blood •serum escapes in “shock” cases to form the condition, which must be cured. Professor Bayliss, the physiologist, came to the conclusion that a more viscous- fluid should -be injected, so that it - would - really add to - the circulating fluid in the body. Gum-arabic,, v one of the gums, completely soluble in water, was selected after considerable experiment, and when -added to the saline solution it has produced remarkable results. The -gum being -easily i accessible" and portable in solution, another curative agent has been added to the repertory of medical men.

% Gums are carbo-hydrates which are exuded from various plants. Gum-arabic pis -.found in Turkey, and is produced by the leguminous plant- gum . mosquite which flourishes in Mexico and Texas. It is yellow in color, brittle, and so soluble in water that it has a wide range of uses. It is used-medicinally as a softener and soother for the tissues, and plays a considerable part in confectionery. Commoner varieties are used for pastes and gums, and its tendency to crack is modified by the addition of glycerine or sugar. The finish of silks ; and crapes is often due to gum-arabic; and calico and cloth manufacture also find uses for it. Gum dragon or gum tragacanth is produced by a plant which, grows in the,: Smyrna ..-district of Asia Minor. The - lower part of the plant is cut during the hot weather, and a white flaky substance exudes. It is chiefly produced during the night, and the flakes-’ show characteristic ripple marks. . This gum is only slightly soluble in water, and the >residue can only .be’ dissolvedrby continued boiling. Its .uses are similar to those of gum-arabic, axxd it is.:valuable as a thickener of:mordants and colors for calico printing. . ~

f Other, substances which are frequently called and frequently look like gums are the gum-resins and resins. The gum-resins contain some true gum, soluble in water; : and some true , resin, insoluble in water but soluble in alcohol. They * also: contains essential .* oils; - Such “gums” have a characteristic. smell, whereas- the true gums , and the true resins are inodorous... Some essential oils are produced by ’the gum-resinsammo-, niacum, myrrh, asafoetida, and (gamboge ; and , they have a wide range of uses in medicine. The resins are also secretions from ,plants out of ! which they are exuded in,;pear-shaped, drops,,; which harden into,, glassy solid masses in .the air. Like the true gums they can be produced in greater quantities by making cuttings in the bark of the plants, and most plants will yield resin when treated with alcohol. . Some of the “most 1 ' Valuable resins are , soft, and ’ are called deo-resins; put if they contain benzoic acid or cinnamic acid they are called halsaams. ~ Examples of "''deb-resins are tur-pentine';-frankincense, and copaiba. Of the hard resins, some are 1 fossil resins, the ! most famous being amber. A. semi-fossil - resin is the well-known v kauri yum of New Zealand, which finds employment for a great body of labor. The use of this resin for varnish and |emenj makes it most valuable. Kauri gum is exuded !: to-day from - the kauri - tree, in the forks of which it ipiay.-be vfound. -Hut it is obtained, more, easily and

in much, greater quantities by digging in the •ground. The annual export is- worth oVbr £400,000? to Zealand, and gum getting has become a considerable industry. With [that thoughtlessness which characterises our attitude to everything that seems prolific the gum was first; picked from the surface, sold by the picker, and shipped to England or America. Tow day the gum areas, where once flourished forests of great kauri, are under the control of Government, and the fields are most systematically searched. There are several layers; of the gum, and it is found deeper than 20 feet. Spears" ten feet long, *or longer, were formerly used and 'are 4 frequently used now in searching for gum. The spear is. thrust into the ground, and when kauri stumps are found the gum is brought : up -by means of hooks. But the systematic' search includes a careful digging over great areasn and the .sifting; of the soil cast up. | Sometimes -* the lump of resin is as large as a turnip ; sometimes it may be: no larger than an egg. At times, especially, in swamp areas, it is very dark, and almost, black. At other times it may be almost transparent. ' It is - this variety which is. the most valuable ; and it realises a considerable price. Atom, in Everyman.