A mercury seal for stirrers - Journal of Chemical Education (ACS

Publication Date: July 1934. Cite this:J. Chem. Educ. 11, 7, XXX-XXX. Note: In lieu of an abstract, this is the article's first page. Click to increas...
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come, spoke of the inspiration to Spanish chemists that would undoubtedly result from this Congress. In the plans drawn up by the International Committee last summer, conspicuous place was given on the program to young men. There were a goodly number of these who were esteemed worthy of such honor. This is very encouraging for Spaniards. Spain is rich in mineral wealth. Its mines of pyrite are the richest in the world, having yielded during the past year 1,831,000 tons for export. Mercury, zinc, galena, manganese, phosphate, and potash deposits of extraordinary abundance are only a few of the mineral deposits. From early Roman times many of the mines have been worked. Spaniards have been in no sense unaware of the existence of these potential riches, hut they have lacked initiative in the past, and the mines have generally been in the hands of foreigners. The situation is changing. That there is change is largely due to the wnstant effort, pressure, and initiative of the Junta para Ampliacidn de 10s Estudios Cient&os. This is a government committee organized more than thirty years ago to improve university education. To

A MERCURY SEAL FOR STIRRERS D. T. ROGERS Rensseker Polytechnic Institute, Troy, New

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MERCURY seal made from stainless steel (Allegheny No. 22) was recently described by the author.' This seal (Figure 1) was intended for use with diierent sizes of glass, steel, or brass stimngrods and at relatively low speeds. For this purpose it was satisfactory but for use at sustained high speeds the seal described in this article (Figures 2 and 3) has been found more satisfactory. To reduce vibration two bearing surfaces (E) and ( F ) (Figure 21, which just allow free turning of the stirring-shaft ( A ) , are fastened to the body of the seal. In those cases where stirring is to he coutinued overnight or where very rapid stirring is desired, it is more convenient to havethetube k2q (D), which rnns in F,,,,, FIGURE 2 the mercury, rigidly attached to the stirring-shaft ( A ) . This is arranged ' D. T. ROGERS, 3. Am. Chn. Sac., 55,4901 (1933).

this end young men who had successfully finished their university careers, were sent abroad to study-to Paris, to Germany, to England. The committee's work did not end here, for, when these young men returned, trained in foreign ways, with their eyes opened to their opportunity, the committee provided libraries and lahoratories in which they could carry on their research. These young men later became the professors in the University of Madrid and in the institutes and universities all over Spain. Elementary schools, residenaas, or dormitories where the social and intellectual life is developed and encouraged, have been established for both men and women of the Central University. I t is impossible to tell all that has been done for education here by the Junta. That is another and longer story.* But this Congress, in charge of the men who have been benefited by the ideals of the Junta fiara Ampliacibn de 10s Estudios Ciatificos, is the concrete evidence of the worth of those ideals.

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* See m y article "The triumph of education in Spain," U. of Chicago Magmine, July. 1931.

by forang (C) into (D) and boring (() so that and (D) as a unit can just he slipped up and down the stirrer-shaft ( A ) . When the desired position is reached (determined by the size of the flask used) the set-screw (B) maintains the adjustment. The shaft (A) and the parts (B), (0,and (D) rotate as a unit. An absolutely moisture-proof and airtight seal is obtained by applying a drop of Insolac to the upper junction of ( C ) and (A). The projection (G), on which the bored stopper is placed, is tapered (not shown in the diagram). Dimensions are such that stoppers can be changed without dismantling the seal. The external features of the seal are shown in Figure 3. The stimng-blades are so designed that they do not fall below a horizontal position but they can be pushed up to the vertical when the stirrer is being put into the flask. A bolt and screw arrangement permits easy changing of the blades. The entire seal and stirrer are made from Allegheny No. 22. Seals made of this alloy have been in continuous use for over a year in this laboratory and are as yet untarnished. The seals were made by A. Bigelman, 1314 Third Avenue, Watervliet, New York.

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