T H E JOliRiVAL OF I N D U S T R I A L A N D EA’GIA-EERIXG C H E M I S T R Y . I n connection with the exhibition, a conference of rubber manufacturers, producers and experts was held for the purpose of promoting knowledge of crude rubber and rubber products. A number of special papers were presented and in the topical discussions on specifications for fire hose, steam hose, insulated wire, and packings much of interest was brought out. The next International Rubber Exhibition is to be held in London W. A. HAMOR. in June, 1914.
THE UNDERWRITERS’ LABORATORIES EXTRACTION APPARATUS: A NOTE. Received September 26, 1912.
Editor of the Journal of Industrial and Engineering Chemistry: On page 535 of your July number of this year, under the heading “ The Underwriters’ Laboratories Extraction Apparatus, ” the Chemical Department of the Underwriters’ Laboratories is credited with the design of a n extractor that was in reality designed by Mr. G. T. Cottle, the chemist of the New York Insulated Wire Co., some four years or more ago. The Underwriters’ Laboratories are indebted for the idea to a drawing of Mr. Cottle’s apparatus that was given them a little over eighteen months ago. Several months before the article in question was received by you, Mr. Cottle exhibited blueprints of the most recent form of it to various chemists of the rubber industry who had not previously been informed about it and arranged to send copies to such as mere interested, and it is already known to a considerable number of analysts of rubber as the “Cottle extractor. ” The author of this article further credits the Chemical Department of the Underwriters’ Laboratories with having ‘‘ spent several years in developing methods and apparatus to be used in a standard procedure for chemical tests of rubber compounds used on wires and cords,” which methods they are ready to distribute. I therefore feel obliged to state that the methods referred to, a copy of which has since been sent me, are actually the joint work of several chemists of the insulated wire industry and that they completed the work without the smallest assistance from the Underwriters’ Laboratories. The complete procedure was then given to the Underwriters’ Laboratories, who, excepting one or two slight verbal changes, the result of which was to make the procedure somewhat less definite, and the addition of alternative methods for ash and total sulphur, also tending to make them less definite, published it verbatim as the “Underwriters’ Laboratories’ Methods of Procedure for Chemical Tests of Rubber Compounds Used on Wires and Cords.” Appended to this, on a sheet marked “ Extractors, underwriters’ Laboratories Inc. ” they publish a copy of the drawing that had been given them of the Cottle extractor. I a m informed that the author of the article in the July number of THISJOURNAL is not connected with the Underwriters’ Laboratories and does not represent them in any way. He was probably laboring under the misunderstanding that .would naturally result from the manner in which this material has been published by them, a misunderstanding that seems to be somewhat wide-spread. The men who gave this procedure to the Underwriters’ Laboratories presumably acted in that spirit of helpfulness that is common enough among chemists. They could hardly have anticipated the liberties that were to be taken with their work. In the case of the Cottle extractor I think some public acknowledgment is due the actual designer of the apparatus. The design is novel and presents certain practical advantages over previous extractors that become obvious under the conditions of service required by the rubber analyst. First of all it is extremely simple. I t consists merely of a spiral condenser of one-eighth inch block tin tube that will slip into the neck of an ordinary 300 cc. Erlenmeyer flask of Jena glass, which forms the external part of the apparatus, and an extraction cup which hangs from the condenser, and which, in its
Nov.,
1912
latest form, is simply a piece of glass tube with a wire gauze bottom. Such flasks are always ready to hand, and both condenser and extraction tube can be made by the chemist in a few minutes from stock materials. It costs only a fraction of the price of an ordinary extraction apparatus to make it, and it is much less liable to breakage. It dispenses altogether with joints, which for various reasons are generally unsatisfactory, however made. As compared with the ll’iley extractor, which it resembles in some respects, it has the advantage of better means for handling the extract, of greater simplicity of construction, of being more readily heated, and of not requiring any support to hold it upright. I n general convenience and effectiveness it leaves nothing to be desired. The apparatus as described in the July number of THIS JOURNAL presents no practical advantage that was not present in Mr. Cottle’s original design. I t does show some not very obvious changes in detail that are either immaterial or to its disadvantage. By making the flask taller and narrower the apparatus is made top-heavy. Nothing is gained in convenience by this. The chemical balances in commonest use can take a 300 cc. or even a 500 cc. flask, and those that cannot, can be provided with a suitable pair of wide bows to support.the pans a t a cost of fifty cents. The addition of a cap to the condenser is unessential unless the apparatus is used on a water bath, and a water bath is not a suitable means of heating a n extractor of this type, even if covered. The special form of flask and the condenser with cap have the additional disadvantage of having to be made by experts, so that the chemist is made more completely dependent on the manufacture of apparatus for his parts. The same is to some extent true of the use of the Gooch crucible as a n extraction cup. So altogether the result is to increase the cost without increasing the value. For all that is effective in the design of this extractor the Underwriters’ Laboratories are indebted to Mr. Cottle’s drawing, as originally submitted to them, and he is entitled to full and exclusive credit for it. Under the circumstances it is a matter of surprise to me that the Underwriters’ Laboratories have not already made public acknowledgment of this themselves. Very truly yours, G. H.SAVAGE. I8 WALNUT STREET,
MASS. WORCESTER,
BUREAU OF STANDARDS ANALYZED SAMPLES. The Bureau of Standards, Washington, D. C., is now prepared to issue pure sodium oxalate for use as a standard in oxidimetry, in bottles containing IZO and 2 0 0 grams, the fees for which are respectively $ 2 . 0 0 and $3.00. With each sample is furnished a certificate giving the purity of the material, and brief directions for its use in the standardization of permanganate solutions. Circular No. 40, on “Sodium Oxalate as a Standard in Volumetric Analysis,” is now ready for distribution and will be sent upon request. I t includes a description of properties, preparation and testing of sodium oxalate, and a discussion of its suitability as a standard in oxidimetry and acidimetry. The fourth edition of Circular 25, “Standard Analyzed Samples-General Information,” is now ready for distribution. Attention is called to the fact that the fee for sample No. z+, Vanadium Steel, has been changed from $2.00 to $2.50. Chrome-tungsten Steel, No. 3 1 , is now ready for distribution. THE DETERMINATION O F BENZALDEHYDE, MARASCHINO CHERRIES AND MARASCHINO LIQUEUR: A CORRECTION. I n the article on this subject on page 589 of the August number of THIS JOURNAL the directions for the procedure (opposite Table IV) should read, “Add I O cc. of the reagent,” etc., instead of IOO cc. A. G. WOODMAN.
