494 Scientific Intelligence. 



precipitate begins to appear after 50 minutes. Then after passing 

 the gas for half an hour longer, when the precipitation is usually 

 finished, the liquid is boiled for a short time, and the precipitate 

 is allowed to settle over night before filtering. The authors have 

 obtained very satisfactory results with these separations, but 

 much seems to depend upon the proper conditions in making the 

 fusion with sodium carbonate and nitrate. The original article 

 should be consulted in regard to further details.. — Zeitschr. 

 anorgan. Chem., lxiv, 65. h. l. w. 



2. Electrical discharges from Radium Emanation. — In con- 

 nection with work on the collection of the emanation from about 

 0-2 g. of radium, Debierne has observed spontaneous electric dis- 

 charges visible in daylight, in the little tubes containing the 

 emanation at atmospheric pressure. The sparks are often as 

 frequent as once a minute, and are sometimes several millimeters 

 in length. They are usually produced in the interior of the glass 

 of the capillary tube, which is then furrowed with little cracks 

 resulting from their passage. The sparks often start from a very 

 brilliant point on the surface of the tube in contrast with the 

 emanation. Sometimes the electric discharge is produced across 

 the emanation itself, which is rather brightly illuminated. These 

 discharges are only produced with certain kinds of glass. A glass 

 w 7 hich showed them most often was one containing lead, which 

 became violet under the action of the emanation, but glass con- 

 taining a large proportion of lead did not show the phenomenon. 

 The discharges may be attributed to the accumulation in the glass 

 of the electric charges of the a and /3 rays when the glass is a 

 sufficiently good insulator. — Comptes llendus, cxlviii, 1264. 



h. l. w. 



3. Outlines of Chemistry, by Louis Kahlenbeeg ; 8vo, pp. xix, 

 548. New York, 1909 (The Macmillan Company). — This is a 

 text-book designed for the use of college students. It is intended 

 to represent one year's work in connection with experimental 

 lectures and laboratory exercises, but no directions for experi- 

 ments are included in it. It is a rather large book containing a 

 comparatively large amount of descriptive matter. The theoreti- 

 cal discussions are distributed through the book in connection with 

 the appropriate facts. Quite a little attention is paid to historical 

 matters, and the most important technical applications have been 

 emphasized. In general the work seems to be an excellent one, 

 and sufficiently different from the large number of books of 

 nearly the same scope to be well worthy of existence. Some 

 fault may be found with certain statements in regard to iron 

 and steel, but metallurgical weakness is characteristic of nearly 

 all of our text-books of general chemistry. The author's attitude 

 towards the ion theory of Arrhenius is a surprising one for the 

 present day, for he rejects the theory as untenable, although he 

 gives a fairly extensive discussion of it. Perhaps this attitude 

 towards the ionic hypothesis may be considered preferable to its 

 too enthusiastic use in a text-book of this kind. h. l. w. 



