Chemistry and Physics. 765 



given an account of the practical development of this idea. At 

 first primitive methods, involving much manual labor, were used 

 in harvesting the kelp, but later mechanical reaping devices with 

 band conveyors were installed upon large power scows, so that 

 the harvesting and unloading were accomplished much more 

 economically by machinery. At first the kelp was dried and 

 burnt to produce an ash, containing about 15 per cent of K 2 0, 

 which was used for fertilizers. Afterwards the kelp was dried 

 and only partially incinerated in order to save the greater part 

 of the nitrogen contents of the material and thus increase its 

 value as a fertilizer. In spite of improved methods, however, 

 the production of potash from kelp has been found to be expen- 

 sive, and the industry will be unable to compete with the usual 

 European supply, nor even with our own supply from brines, 

 alunite deposits, recovery from cement kilns, blast furnaces, etc., 

 unless other products can be produced from the kelp. To 

 accomplish this last purpose a factory was started in 1915 at San 

 Diego, California, with the intention of producing acetone, pot- 

 ash and iodine from kelp. For this purpose the kelp is first 

 fermented, whereby acetic acid is formed and the potash and 

 iodine are brought into solution. The acetic acid is neutralized 

 with limestone, forming calcium acetate, which upon ignition 

 yields the important solvent, acetone, while the iodine is saved 

 and the potash is finally obtained as potassium chloride. As the 

 process has developed other products have been made, so that this 

 method appears to be a promising one. It is stated that not 

 more than 25 tons per day, on the basis of 80 per cent muriate 

 of potash, are produced by all the kelp-harvesting concerns at the 

 present time, and that more than half of this is produced by the 

 fermentation process. — Jour. Indust. Engr. Chem., 10, 832. 



h. l. w. 



3. Treatise on Applied Analytical Chemistry, by Vittorio 

 Villavecchia. Translated by Thomas H. Pope. Vol. II, 8vo, 

 pp. 536. Philadelphia, 1918 (P. Blakiston's Son & Co.).— The 

 first volume of this excellent work, which has been prepared with 

 the collaboration of nine other experts, was noticed and highly 

 praised in the April number of the Journal of the present year. 

 The present volume completes the work and deals with meat and 

 its preparations, milk and its products, sugars and products con- 

 taining tliem, beer, wine, spirits, and liquors, essential oils, tur- 

 pentine and its products, varnishes, rubber and guttapercha, 

 tanning products, inks, leather, coloring matter and textile fibers, 

 yarns, fabrics. This volume, like its predecessor, has the excel- 

 lent features of being clear, practical, and satisfactory in the 

 selection of methods of analysis, and in giving valuable notes in 

 regard to the interpretation of results. h. l. w. 



4. Outlines of Theoretical Chemistry ; by Frederick H. Get- 

 man. 8vo, pp. 539. New York, 1918 (John Wiley & Sons, 



