The Prescott daily news., 1915-01-05
P1TBER AS A SOURCE OF DANGER

iStry or ruDUSI pSS'uoC eiiio hi"ool io'i onters into numberous articles and devices of daily use. Experience teaches the unlike qualities of differ ent types or brands of rubber. Some of them retain their original elasti- city for a long time under the imposed conditions of usage, while others speedily deterioate into brittle and useless scrap despite the various pre- cautions of preservation that are en- hodied in familiar directions. The ec- onomic aspect of the quality of rubber coods offered for sale is an important one.
 The time is arriving, says The Jour- nal of the American Medical AssOcia- ton. when the purchaser of rubber will demand some reliable information as to the quality of the product which he is paying for. Rare, indeed, is the person at the present time who has any idea whatever of the makeup of rubber. Pure india-rubber, or caou- tchouc, in. it's natural state is entirely unsuited for commercial use. It is soft and sticky, and readily undergoes spontaneous oxidation to a hard, brit tie resinous substance. By vulcani- zation, a process in which mixtures of crude gum with sulphur, or metal lie sulphids or oxids are heated, a rub Der is formed which is more perman- ently elastic and less subject to spon- taneous change. The simplest type of vulcanized rubber, such as would be obtained from properly heated mixture of sulphur and pure gum, is quite soft and offers little resis- tance to ordinary rough usage. Rub Der of tougher qualities, but with low CT elastic limits, is produced by the addition of metallic oxids, such as those of lead and of zinc, to the other ingredients before vulcanization. Among other constituents added to give required characteristics are the various pigments which furnish the color, Venetian red (iron oxid), ultra marine, lampblack and various organ ic dyes being among the ingredients which are employed.
 A recent government report shows that a large number of materials are used in rubber compromising to reduce the cost. Among these are whiting, barytes, clay and various rubber sub stitutes, such as artificial rubber, oils and tar products. Finally, so-called recovered rubber, or shoddy. is used to a large extent in rubber compound In the case of most articles of rubber the existence of filling materials, pig ments, etc., has no hygenic import. Cost and durability are the chief con- cern of the purchaser. The use of various heavy metals in the manufac- ture of nursing nipples and small rub Der toys is danger to the health of infants, who extract soluble products from such articles in the mouth or when small pieces of the rubber are accidentally swallowed
 The Public Health Service has late ly investigated the rubber used in nipples and toys. All specimens eX- amlned contained iron and aluminium In the red rubbers either zinc oxid or magnesia was used, in the black rub oers zinc oxid and barytes. Anthony was found in four cases out of seven among the black rubbers and in five cases out of eight among the red rubbers. The three remaining speci- mems of red rubber were colored with Venetian red. The white rubber toys contained clay, zinc oxid and barytes. Inc use of lead compounds in rubber preparations is common, and salts of mercury are used to some extent Either of these metals would be high " objectionable in nipples or child ren's toys. The government report concludes: The articles should be made of good grade of black rubber lree from shoddy and from antimony, lead, arsenic and mercury. Of the nllers commonly employed, magnesia zinc oxid and clay are less undesir- able, There can be no objection to a red rubber colored with iron oxid, al-- though the advantages of such a com pound will probably not compensate TOT the disadvantages of it's heinz confused with antimony rubber.
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