MOTHS AND WOOL.

Otago Daily Times, Issue 19498, 5 June 1925, Page 10

MOTHS AND WOOL.

HEW TREATMENT FOE CLOTH, By far the greater part of mankind are clad in garments of wool or cotton, or a mixture of the two, hence the ravages of two tiny insects, the clothes moth and the boil weevil, oome home to all of ns. The damage done to them, indeed, amounts to millions of dollars annually. It is good news, therefore, to learn that a method has been, found to spoil the appetite of the former at least. This is done by treating the wool or woollen goods with a newlydiscovered chemical which is highly offensive to moths, though it is both odourless and colourless. Writing in Kosmos (Stuttgart), Dr George Stehli gives the following account:—“According to Titschack, the progeny of a single female moth, even if only 50 per cent, of the eggs, which average 130, leach maturity and if 33 per cent, of these are females, is sufficient (counting four, generations to a year) to destroy 42 kilograms of wool. . . . Some success has recently been obtained by treatment with hydrocyanic acid and with "Eyklon/’ a mixture of which acta in the same manner. . . . in large warehouses holding woollen goods. This process, however, can never find extended application for household purposes because of the trouble, expense, and danger by which it is attended.” As to the use of cold. Dr Stehli observes that moths possess considerable resistance to cold, and that anyway such a method is not capable of general use. The newest process is to protect the wool by the substance referred to above, which has the effect of making the material moth-proof. This material has been named “eulan,” and is also called ‘motheulan,” especially in the drug trade, which now handles.it so that it can he more readily accessible to housewives, Eulan was discovered by a chemist named Meckbach as a result of a series of experiments which began as far back as 1915. and which were based upon the observed fact that moths avoid cloth coloured with certain dyes, such, for example, as eosin. Dr Stehli says; “I have subjected woollen material made mothproof by eulan to the most thoroughgoing testa in order to study the effects produced upon the larvse of the clothes moth, using controls of untreated woollen materials. After the lapse of a year I am prepared to give my positive affirmation that wool treated with eulan is perfectly safe from attacks by moths. I placed the caterpillars of. all ages upon the untreated cloth, where they «oon began to make their characteristic tubes, so that after the lapse of a year the material represented a very labyrinth of holes and tubes, empty cocoon cases, etc. . . . Upon - the material trea.ted with eulan, on the other hand, there was not the faintest trace of any injury to be discovered even upon examination under the microscope. “How can we explain this? Apparently through the fact that as soon as the caterpillars have eaten the tiniest slired of wool and thus swallowed some of the eulan they lose their appetities entirely and die of starvation. I was led to this conclusion by the great mortality observed among the caterpillars when placed upon material previously treated with the eulan. While at first they tried to get away from the surface of the material and ran hither and thither, later they remained quiet but without spinning theniselves fast and without eating, apparently stupefied, until they perished of starvation. It is also conceivable, as Haase supposes. that they are poisoned by the specific action of the preparation.