INDUSTRIAL AND ENGINEERING CHEMISTRY
586
Cleaning Laboratory Glassware DANIEL L. HARRIS AND HERSCHEL K. MITCHELL School of Biological Sciences, Stanford University, Calif.
THE
device illustrated in Figure 1 has proved particularly useful in cleaning laboratory glassware with corrosive fluid. such as chromic acid or sulfuricnitric acid mixtures. It is also useful for .drying glassware with organic solvents such as acetone, or for making collodion membranes in test tubes. T h e unit is constructed of Pyrex and can be heated directly if hot cleaning solution is desired.
In operation, a flask, beaker,
Figure I. Apparatus A , 4 to 5-inch funnel, R , 0.5
to 1 .O-liter Rarkl C, constriction in 10-mm. lube, internel diameter 9. to 3 mm D medicine6d-ml. rubber d r o h e r bulb, bulb, F, 8-mm. tubing, C, throat, about 18-mm. internal diameter
8,
etc., is inverted inside t h e funnel, A directly over the throat, G. Abrupt pressure on t h e rubber bulb, E, produces a strong jet of fluid which floods t h e walls of t h e vessel and then drains back into t h e funnel. On release of the bulb, the excess fluid is sucked back into chamber B. Flasks, test tubes, beakers, bottles, and graduates are acid-cleaned in this manner very rapidly. Flasks, for example, have been acidtreated a t a rate of over 750 per hour.
If the vessels being cleaned contain a large amount of reducing material which can wash back into the chamber, the cleaning solution will deteriorate. However, in normal use this does not occur. Most of the cleaning action probably occurs in the film of acid left in t h e flask. T h a t this film of acid is sufficient to clean the glassware thoroughly, if the flasks are left standing for a short time, is indicated by the fact t h a t after rinsing with distilled water, interference rings form within 1 or 2 minutes. T h e small medicine-dropper bulb, D, is removed when thc chamber is being filled. T o prevent accidents, it is wise t o remove D whenever the device is not actually in use.
BOOK REVIEWS Qualitative Organic Microanalysis. Frank Schneider. iv f 218 pages. John Wiley & Sons, Inc., 440 Fourth Ave, New York 16, N. Y., 1946. Price, $3.50. In this short book the author has attempted to create a “guide to the microtechniques required for the identification of organic compounds”. The first half of the manual consists of a compilation of numerous published micromethods applicable to fundamental organic operations. The latter half is an abbreviated treatment of the problems of qualitative organic analysis along with laboratory directions for preparing about 30 derivatives. Techniques of separation and the handling of mixtures are not adequately treated by the author, and consequently he had no reason to dibcuss some of the newer practical micromethods for this work. One thinks particularly of diffusion halysis and chromatography. The latter might have been mentioned under the heading “purification of the sample”. Since many difficult industrial problems in the field of organic identification are being solved Every day by methods of chemical niicroar’opy, it would seem that the author ought to have offered more Fncouragement to the reader in the use cjf the microscope as a tool in organic analysis. He mentions the scarcity of optical data fcr organic compounds; yet he does not list even the most valuable literature sources cf such data now in existence. For instance, there is nomen-
Vol. 18, No. 9
tion of Winchell’s recent book which lists optical data for over a thousand organic compounds. or of the Barker tables which are being published in England. The first portion of the book dealing with organic operations is abundantly provided with diagrams of the microapparatus recommended. Such a collection should prove a useful reminder to even the experienced organic chemist who may have seen them before. Unfortunately some of the pieces drawn are too large to be practical for true microwork-i.e., 30 to 100 mg. of substance-being more suitable for “submacro” work, 0.5 to 1.5 ml. Yet this criticism does not detract from the usefulness of the manual. The book is free from typographical errors and is attractively printed in a medium-sized type suitable for student use. On pages 121 and 122 the author uses “crystalline form” indiscriminately when he means “crystal habit” in some instances. Another slip is the frequent use of the word “microscopic” for the more appropriate “microscopical”. In spite of our criticism the book fills a useful purpose and is a pioneer in the field which it covers. J. A. KUCK Standard Methods for Testing Petroleum and Its Products. 7th edition. 550 pages. Institute of Petroleum, 26 Portland Place, London, W.1, England; and American Society for Testing Materials, 1916 Race St., Philadelphia 3, Pa. Price, 15s. or $3.25. An added feature is a list of new methods, revisions of methods and specifications, and withdrawals: Two new methods have been added, and 21 standards and two specifications have been effected by various changes. The conversion tables for petroleum oils have been withdrawn. One of the new methods is a modification of a test for the determination of carbon disulfide in tar and its products to be applied to petroleum products. The other new method is intended to detect the coagulation of bitumen emulsions a t low temperatures. The method for knock rating of aviation fuel (weak mixture) has been rewritten to correspond to the A.S.T.M. format. Several changes have been made in the knock rating methods for experimental fuels over 100-octane number and for motor fuel. Changes in procedure and interpretation of tests are few. A larger sample is permitted in the test for low acidity. Copper strip tests for corrosive sulfur are to be interpreted as one of six classifications of color change. Methods for the determination of tetraethyllead in motor fuel by bromination and hydrochloric acid are modified. The bromination method is not applicable directly t o blends containing alcohol and is not recommended for fuels containing a high percentage of unsaturated hydrocarbons. Modifications are indicated in apparatus for the following methods: distillation of liquid asphaltic bitumen, drop point of greases, dash point (closed) by means of the Pensky-Martens apparatus, penetration of bituminous materials, recovery of asphaltic bitumen from asphalts, residue on evaporation of kerosene and tractor fuel, sludging value of transformer oil, softening point of asphaltic bitumen (ringand-ball method), viscosity by the Redwood apparatus, and water and sediment by means of centrifuge. Editorial changes have been made in methods for ash of petroleum products, color by means of the Lovibond tintometer, distillation of crude petroleum, and sampling petroleum and petroleum products. The title of the specification for wartime hydrometers now has an emergency status. Modifications in the specifications for wartime standard thermometers are more extensive. F. E. BUCHAN
Abstract s-S
pec t r oc hem ica I A n a Iy s is
The Ohio Valley Spectrographic Society announces the publication and distribution of Collected Abstracts Published during 1945 on Spectrochemical Analysis, compiled by Edwin S. Hodge. The 64page lithographed booklet contains verbatim copy of all the abstracts published in 1945 by Chemical Abstracts on articles dealing with spectrochemical analysis. Over 80 references are cited, covering all the latest reported developments in the science, including analysis of alloys, direct-reading instruments, and other progress. The subject matter is arranged according to twelve topics and is well indexed. The book is available from the Ohio Valley Spectrographic Society, Engineers Club Bldg., Dayton, Ohio, at $1 per copy if rash is sent with order; $1.25 when billing is required.
