76 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. The Analysis of Pyroliislte and other Oxidized 3Ianganese 

 Ores. — O. L. BAnisrEBY and Geo. M. Bishop have devised a veiy 



simple and convenient iodometric method for the determination 

 of active oxygen in these ores. A sample of about 0*2 g. of the 

 very finely powdered ore is placed in an Erlenmeyer flask with 

 10^"^ of a normal solution of potassium or sodium iodide, followed 

 Jby 5" of concentrated hydrochloric acid. The flask, covered 

 with a watch glass, is allowed to stand with frequent shaking 

 until the reaction is complete. Under these circumstances iodine 

 is liberated, not only by the higher oxides of manganese, but 

 also by the ferric oxide that is always present in the ores. Then 

 from 0'2 to 0*5 g. of powdered sodium tartrate is added and the 

 solution is diluted to about 150'^^ This reagent prevents the 

 subsequent precipitation of iron b^^ sodium bicarbonate, which is 

 now added in small portions until a considerable excess is present. 

 In the resulting solution the iron is changed back by the free 

 iodine to the ferric condition. The remaining free iodine, corre- 

 sponding to the higher oxides of manganese, is now titrated with 

 standard arsenite solution, using starch as an indicator. — Jour. 

 Amer. Chem. ISoc., xxxix, 1235. h. l. w. 



2. The Life of Robert Hare, an American Chemist; by Edgau 

 Fahs Smith. 8vo, pp. 508. Philadelphia, 1917 (J. B. Lippincott 

 Company). — The present-day student of physics and chemist r}'- 

 may probably know that Robert Hare of the L^niversity of 

 Pennsylvania invented that very important piece of apparatus, 

 the oxy-hydrogen blowpipe, and by its aid succeeded in melting 

 considerable quantities of platinum, and showed that practicall}^ 

 all of the hitherto refractory substances could be melted by the 

 use of this powerful means of heating. The student may have 

 learned also that Hare's '* deflagrator " was a galvanic battery of 

 much importance for currents of great heating power in the times 

 preceding the modern development of electric generators. While 

 these well-known facts indicate the remarkable experimental 

 ability of this early American chemist, the present biography 

 shows him to have been aman of varied and high attainments in 

 science and of admirable personal character. 



Provost Smith has produced a very attractive and interesting 

 biography of his eminent subject. He admits that he has become 

 an enthusiast in regard to him and consequently, while he has 

 allowed Hare himself to tell much of his stor}^, largely through 

 previously unpublished letters and other documents which were 

 buried in forgotten journals and pamphlets, he has evidently 

 devoted a vast amount of research to his task, and his comments 

 show much admiration for his hero. 



