BOOK REVIEWS A N D NOTICES. latter continues down into the base, vvhich contains two or more ordinary incandescent lamps, depending upon the size of the incubator. A mercury thermo-regulator is inserted i n the water jacket, the bulb of which contains about two pounds of mercury and has a capillary glass tube a t tached, through which the expansion and contraction takes place, thus magnifying a n y slight change of temperature.
The current passing through the regulator is automatically closed or opened by the rise or fall of the mercury in the capillary tube, the point of contact being adjusted by turning t h e screw provided for this purpose. The incandescent lamps in the base and the regulator are connected with a make and break device, which constitutes the simple arrangement for maintaining a constant temperature in t h e inner compartment of the incubator and this temperature is noted b y a thermometer, the top of which projects above the top of the apparatus. The oven is entirely surrounded with insulating material a n d is provided with two doors, the outer one being well insulated and the inner one is made of glass, all of the insulating material being finished in white enamel. Tests covering 45 days were made, which showed that the cost of operating was small and t h a t the fluctuation of temperature in the incubator, during this time, was a small fraction of one degree, notwithstanding the temperature of t h e room changed about 18 degrees every 24 hours. T h e incubator is patented and manufactured by Scientific Materials Company, Pittsburg, Pa. CHESTERF . FISHER.
LOSS O F ALCOHOL
FROM LIQUIDS L O W I N ALCOHOL.
T h e attention of the writer was called to this subject by a controversy which occurred between him and a chemist employed by a breuing company as to the percentage of alcohol in a specimen of beer low in alcohol. The results are placed on record; they may be of some interest to other chemists who may have to deal with a similar piece of work Four specimens of the beer in question were analyzed and found t o contain the following percentages of alcohol : 0.94, 0.83, 0.82 a n d 0.74. The beer was contained in the ordinary pint bottles closed with cork-lined tin caps crimped on. I n getting the sample for analysis the caps were loosened just enough to be sprung off; about I I O to 125 cc. were withdrawn a n d t h e caps snapped back i n place. The bottles were returned to t h e source from whence they came and were, after a n interval of about thirty days, sent to a representative of the brewing company which had sold them. The alcohol was then redetermined by the other chemist who reported the percentages of alcohol i n the same order a s found in the original analysis b u t so much below the first figures t h a t none of them exceeded 0.50 per cent. alcohol. It appeared t o the writer to be a matter of some interest to know whether the beer kept under these conditions was likely t o lose a p a r t of the alcohol as was indicated by these figures. Accordingly a bottle of the same brand of beer was analyzed March 15th and found to contain 0.96 per cent. alcohol. It was handled exactly a s the other samples had been except t h a t i t was kept i n the writer's office. On April 23rd the alcohol was redetermined, when i t showed exactly the same percentage as before, 0.96. I n spite, therefore, of the interval of thirty-nine days, no loss of alcohol could be detected. The bottle was kept a s before until May 31st, a further period of thirty-eight days. During this time a small quantity of mould appeared i n the liquid, though i t did not smell sour. The mould was filtered o u t and the alcohol redetermined, mhen i t was found t o be 0.85 per cent. This difference is so slight t h a t i t may possibly be due t o experimental error, b u t seems rather t o indicate a very slight loss of alcohol. T h e results here given show, as a n answer to the main question, t h a t a liquid like the one under discussion does not, under the conditions named, lose more than a trace of alcohol in a period of over t w o and one-half months. W I L L I . E. ~ BENTLEY. ATHENS,OHIO.
BUREAU O F STARDARDS ANALYZED SAMPLES. A sample of acid open-hearth steel with 0.6 carbon is now ready for distribution, also a new sample of Bessemer 0.4 carbon in place of t h a t hitherto supplied b u t now exhausted. The next samples to be ready will probably be basic openhearth 0.4 carbon (renewal) and a vanadium steel with about 0.2 per cent. 5'. Certain iron ores are in preparation, b u t the dates of issue cannot be now given. W. F. HILLEBRAND.
BOOK REVIEWS AND NOTICES. Jahrbuch des Vereins der Spiritus-Fabrikanten in Deutschland, des Vereins der Stdrke Interesenter in Deutschland, and Vereins Deutscher Kartoppel-trockner. Xeunter Jahr-
