Chemistry and Physics. 347 



SCIENTIFIC INTELLIGENCE 



I. Chemistry'^ and Physics. 



1. Metallic Radium. — Mme. Curie and A. Debieene have 

 prepared a sniJiU quantity of radium in the metallic state. Tliey 

 electrolyzed a solution of pure radium chloride containing about 

 O'l g. of the salt, using a platinum anode and a cathode consist- 

 ing of about 10 g. of mercury. In this way an amalgam of 

 radium was produced, and upon distilling off the mercury in an 

 iron boat contained in a quartz tube filled with carefully purified 

 hydrogen, a minute quantity of what was presumably metallic 

 radium was left behind. At 700° C. the metal began to volati- 

 lize and energetically attacked the quartz tube. It has, there- 

 fore, a lower boiling point than metallic barium. The metal 

 shows a brilliant while luster, and it melts at 700°. It is altered 

 very rapidlj' by air, becoming black, probably on account of the 

 formation of nitride. It decomposes water energetically, most of 

 it going into solution, so that the oxide is evidently soluble in 

 Avater. Since the metal is much more volatile than barium, the 

 authors propose to purify it by sublimation in a vacuum upon a 

 sheet of cold metal. — Gomptes Hefidus, cli, 523. h. l. w. 



2. Separation of Antimony and Tin by Distillation. — It is 

 well known that arsenic may be conveniently separated from . 

 other metals for the purpose of quantitative analysis by Emil 

 Fischer's method of distilling with ferrous chloride and hydro- 

 chloric acid. W. Plato has now found that it is possible to 

 distil over antimonic chloride by the use of a stream of hydro- 

 chloric acid gas in a sulphuric acid solution to which phosphoric 

 acid has been added, and which can be heati^d to a suitable tem- 

 perature. The phosphoric acid prevents the distillation of stannic 

 chloride at the same time, but after the antimony has been 

 removed it is possible to distil over stannic chloride by elevating 

 the temperature and usinu hydrobromic acid. For carrying out 

 the operations a special, easily constructed apparatus is described, 

 and test analyses are given which show extremely satisfactory 

 results. The method is recommended for substances containing, 

 besides tin or antimony or both of these, such metals as copper 

 and lead. — Zeitschr. anoi-gan. Chem., Ixviii, 26. h. l. \v. 



3. Essentials of Chemistry ; by Rufus Phillips Williams, 

 12mo, pp. 421. Boston, 1910 (Ginn & Company). — This "experi- 

 mental, descriptive, and theoretical" text-book of elementary 

 chemistry follows a series of briefer works by the same author, 

 which have been extensively used in our schools. In the preface 

 is set forth a list of 21 "innovations and departures from the 

 author's previous works, as well as from current texts." Many 

 of these changes relate to the arrangement of the matter and the 



