Intelligence and Miscellaneous Articles, 369 



runs to 24 pages ; and the specifications of Abel and Tidy, and also 

 the views of Mr. S. B. Boulton (who is, perhaps, the highest autho- 

 rity on the subject living) are given. We should have liked, in this 

 place, to see Dr. Lunge's views as to the part played by the organic 

 alkaloids in creosote oil in the preservation of pickled timber. 



Chapter IX. is on " Carbolic Acid and Naphthalene." The me- 

 thods of preparing carbolic acid of various degrees of purity are 

 given in considerable detail, and also the most reliable modes of 

 testing the various commercial products. The best plans for sub- 

 liming and distilling naphthalene are also fully described. This 

 chapter extends to no less than 56 pages, every one of which is 

 interesting and useful. 



Chapter X. is on " Light Oil and Crude Naphtha." This portion 

 does not admit of any specially original treatment, as the methods 

 now in use are not very different from what they were some years 

 ago. 



Chapter XL, on " Eectifying by Steam ; Final Products," is of 

 great value, and will be greatly appreciated by practical tar- distillers. 

 The stills best adapted for the purpose are represented by engra- 

 vings, and explained in a clear and simple manner. Savalle's and 

 Siemens's apparatus are described very fully, and the directions for 

 their use are sufficient to enable any chemist to work them. The 

 various kinds of benzols, toluols, and naphthas of commerce, with 

 their boiling-points, and the apparatus used for determining the 

 latter, are all given, as also the processes for determining the various 

 constituents of coal-naphtha. The chapter concludes with a synop- 

 tical table of the distillation of coal-tar. 



Chapter XII. commences the second part of the work, which is 

 on Ammonia, by an exhaustive account of the various sources from 

 which that substance is obtained. Then follows Chapter XIII., 

 which gives the composition and analysis of am moniacal liquor and 

 the properties of its constituents. Chapter XIV. is on "The 

 Working-up of Am moniacal Liquor. The work concludes with an 

 Addenda giving a large amount of varied information, much of 

 which will doubtless be incorporated with the earlier articles in 

 subsequent editions. 



This work of Dr. Lunge is by far the most extensive and the 

 best which has appeared in our language on the products of coal- 

 tar, and will be indispensable to every one interested in the impor- 

 tant subject of which it treats. 



XLVIII. Intelligence and Miscellaneous Articles. 



ON A NEW POLAE ACTION OF MAGNETISM ON HEAT IN A PLATE 

 TRAVERSED BY A GALVANIC CURRENT. BY A. VON ETTINGS- 

 HAUSEN. 



Q OME time ago I brought before the Imperial Academy a phe- 

 ^ nomenon observed by myself and Nernst (Phil. Mag. Sept. 1887, 



