184 



SCIENCE. 



[Vol. XXII. No. 557 



thus assuring mixture and oxidation by the uprising 

 current. When the oxidation is complete the air is shut 

 off and the air in the upper parts and in the supply and 

 exit pipes removed by means of steam. Dry steam is 

 then passed. Nitrogen is obtained with a slight modifi- 

 cation, by collecting the gas which escapes during the 

 oxidation and again passing it through the mixture. 

 Electro Deposition of Iridium. 



At the Madison meeting of the American Association, 

 Dr. Wm. L Dudley described his method for maintaining 

 a constant metallic strength and purity in an electro- 

 lytic bath for the deposition of iridium. The electrolytic 

 solution of the metal from an anode was of course desir- 

 able, but was found to be a tedious and expensive pro- 

 cess. Sxiccess was finally attained by the use of (1) an 

 oxide, or (2) a hydroxide, these to be insoluble in the 

 electrolyte but freely soluble in the acid radicle set free 

 at the anode. Iridium hydrate, Ir(OH)^, was employed 

 suspended in loose-fitting linen bags between the carbon 

 anodes. Sodium iridichloride and ammonium iridichlo- 

 ride gave satisfaction as did also a solution of the hydrate 

 in sulphuric acid with the addition of ammonium sul- 

 phate. 



Dr. Wm. H. Wahl had evolved the same process for the^ 

 platinum group after much independent study parallel 

 with that of Dr. Dudley. 



Commercial Organic Compounds by Electrolysis. 



The production of commercial organic compounds by 

 electrolysis is a significant step in the advancement of 

 electrolytic methods. F. Bayer & Co., of Elberfeld, are 

 now producing the periodid es of the phenols and the phenol- 

 carboxylic acids by subjecting mixtures of solutions of the 

 alkaline salts of phenols and of alkaline iodides to the 

 action of the electrical current. A solution of the alka- 

 line iodide is prejjared and in this are immersed the elec- 

 trodes separated by a diaphragm. The current is jaassed 

 and at the same time an alkaline solution of jDhenol is 

 gradually added. Two amperes per square decimetre of 

 electrode surface is sufficient. In a few hours the phenol 

 becomes entirely converted to the periodide, which sepa- 

 rates out in solid form. 



The electrolysis of a solution of ferrous sulphate to 

 which a weak solution of proto-chloride of iron, sodium, 

 potassium, calcium, vanadium or magnesium has been 

 added produces a basic sulphate of the peroxide. Add- 

 ing the equivalent of sulj)huric acid before or after elec- 

 trolysis forms the tri-sulphate of the peroxide of iron 

 which is used in the preparation of dried blood manure. 



MM. Hermite and Dubosc cause ferrous sulphate to 

 circulate in an electrolytic apparatus, arranged to main- 

 tain a maximum amount of the salt in solution, and so ob- 

 tain a saturated solution of the sulphate of the peroxide. 

 By varying the current in density and duration more or 

 less of this salt may be formed, constituting the various 

 mordants known as "rust," " suljDho-nitrate " and " per- 

 sulphate of iron." The apparatus consists of an enameled 

 iron tank with an outlet for draining at the bottom, a per- 

 forated pipe in the lower part for supplying the solution, 

 and an overflow at the top. The electrodes are jjlates of 

 iron and thin sheets of platinum. 



Determination of Iron and Silicon in Commercial Aluminum. 



Dr. A. EoESSEL gives the following process for the de- 

 termination of iron and silicon in commercial aluminum. 

 Three to four grammes of the metal are gradually intro- 

 duced into 35 cc. of hot potash lye (30-40 per cent). The 

 metal dissolves leaving a black floculent residue. The solu- 

 tion is now supersaturated with jJure hydrochloric acid in 

 a platinum crucible without previous filtration, and is then 

 evaporated to dryness. The mass is moistened with hy- 



drochloric and the silica is determined in the ordinary 

 way. For the determination of the iron, Eoessel dis- 

 solves 3-5 grammes of aluminum as before and mixes 

 with an excess of dilute sulphuric acid. The solution is 

 heated until clear and is then titrated with potassium 

 permanganate. The potash-lye used must, of course, be 

 tested for silica. 



NOTES AND NEWS. 



The American Book Compaist have issued several books 

 for the study of classics, some of them new, and some 

 merely new editions. Of the latter class are "Arnold's 

 First and Second Latin Book" in one volume and "Arnold's 

 Latin Prose Composition." These works, which have 

 been in use for many years, have been revised by James 

 E. Mulhoiland; the revision being confined to the correc- 

 tion of errors and a few minor additions, without chang- 

 ing the essential character of the original works. The 

 two other classical books that lie before us belong to the 

 series of which President Harper, of the University of 

 Chicago, is one of the editors. In editing "The Aeneid 

 (six books) and Bucolics of Vergil" Mr. Harper has been 

 assisted by Frank J. Miller, instructor in Latin in the 

 same university; and the edition they have prepared dif- 

 fers in some respects from most of those now in use. An 

 important feature of the work is the series of "Inductive 

 Studies," mostly grammatical, which precede the poem 

 itself, and in connection with the notes and the vocabu- 

 lary, are designed to give the student his grammar, notes 

 and lexicon all ig one volume. The book also contains 

 twelve full-page illustrations, being reproductions of 

 noted works of art. The other volume in the same series 

 is an edition of the whole of "Xenophon's Anabasis," pre- 

 pared by President Harper and James Wallace of Macal- 

 ister College. This also contains inductive exercises and 

 other grammatical helps, together with notes and a vocab- 

 ulary. There is also an introduction showing the histor- 

 ical setting of the Anabasis, with a description of the 

 Greek and the Persian modes of warfare and many pic- 

 torial illustrations of warlike material and other apjDurte- 

 nances of ancient life. These books are well printed and 

 substantially bound. 



— The Minnesota Academy of Natural Sciences, in con- 

 junction with the St. Paul Academy of Sciences, made an 

 excursion on Sept. 16 to Taylor's Falls, on the St. Croix 

 River. The party numbered eighty persons. The sand- 

 stones overlying the Cambrian igneous rocks through 

 which the St. Croix Eiver passes, forming a beautiful ero- 

 sion gorge and the bowlder conglomerate formed of the 

 broken down igneous rock were inspected. The early 

 age of the conglomerate is demonstrated by the presence 

 in it and in the cementing sand of fossils of certain date. 

 Pot-holes of great size are seen there, one into which ac- 

 cess is possible holds more than twenty j)ersons at one 

 time. 



— Messrs. Macmillan & Co. announce a second edition 

 of Professor Goldwin Smith's brilliant sketch of the 

 United States, the first edition of which was exhausted in 

 two weeks. Written by an Englishman who regards the 

 American commonwealth as "the greatest achievement of 

 his race," this book must possess a peculiar interest for 

 American readers. 



— M. L. Holbrook, New York, will publish early in the 

 Autumn another book by Bertha Meyer, author of " From 

 the Cradle to the School," entitled, "The Child, Physically 

 and Mentally; Advice of a Mother according to the 

 Teaching and Experience of Hygienic Science ; a Guide 

 for Mothers and Educators." It has been translated by 

 Friederike Salomon, revised by A. R. Aldrich. 



