CIIKM1STKV. 



117 





cobalt, nickel, /.inc. cadmium, l>iMiuith, copper, 

 it-y. silver, gold, tin, platinum, and unti- 

 IUIM- IHVII separated as metals, and manga- 

 nese and lead as peroxides. Some of these metals 



il dillicull les in elect rolysis, because they 



form a uniform adhesive stratum only if present 



in small miantities. A uniform adhesive coating 



obtained by adding such metals as are 



apt t" !'< deposited as a spongy mass, for which 



mirjxisc mercury i< convenient. Hy this method 



Vortmann has made a scries of very interesting 



elect r,,l\ses, which are described in detail in his 



in the Itrrichte of the Deutsche Chemisette 



Ibchaft. 



The a-licstos method of milk analysis as de- 

 d by Thomas Mticfarlane to the Royal So- 

 ciety of Canada, in May, 1887, has proved so 

 satisfactory at the Canada Experimental Farm, 

 l>tli HS to accuracy and rapidity, that it has 

 been adopted in the laboratory of the farm. Mr. 

 Frank T. Shutt gives accounts of experiments, 

 contrasting this process with others in which the 

 total solids are estimated by evaporation in plati- 

 num dishes, and in which "the fat is determined 

 by weighing in flasks after exhaustion of the 

 milk solids in a Soxhlet tube. In the former ex- 

 ]K>rimcnts the solids obtained were higher by the 

 platinum method, but are believed to have been 

 too high. It is observed that while the milk 

 solids in the asbestos method are always white, 

 those in the platinum method are more or less 

 brown, showing that a change takes place in the 

 latter process which does not ensue by the asbes- 

 tos method. In the second series of experiments 

 the results obtained by direct weighing were 

 slightly the higher of the two. If it be granted 

 that the total solids and fat can be accurately 

 determined by this method, Mr. Shutt's tables 

 show that the results are not variable, and that 

 when duplicates are performed no large differ- 

 ences will have to be averaged in order to arrive 

 at the truth. 



It is remarked by Mr. T. W. Hogg that the 

 method of determining iron in its alloys by de- 

 composing with dilute hydrochloric or sulphuric 

 acid, and oxidizing by means of a standard solu- 

 tion of bichromate of potash, is liable to error 

 when copper is present. In such case the author 

 advises solution in dilute hydrocloric acid, add- 

 ing potassic chlorate, and boiling to expel chlorine 

 compounds. The iron may then be reduced by 

 means of a solution of sodium sulphite, and, 

 after boiling away the excess of sodium sulphite, 

 adding the bichromate in the usual manner. 



For detecting metallic silver in the presence 

 of lead, Alexander Johnstone suggests boiling 

 the product obtained by heating the mineral 

 with fusion mixture in nitric acid: neutraliz- 

 ing the solution with sodium carbonate, but leav- 

 ing it slightly acid; and inserting in the pre- 

 pared solution a strip of copper and one of zinc. 

 The lead of the solution is deposited on the zinc, 

 and most of the silver on the copper. This is 

 then tested. If no silver is present in the solu- 

 tion, the copper foil when placed in it is hardly 

 coated. 



The novelty in Herr J. Wiborgh's volumetric 

 method of estimating carbon in iron consists in 

 the direct measurement of the carbonic acid pro- 

 duced from the oxidation of the carbon in the 

 sample under investigation instead of weighing 



it as potassium carbonate, as is usually done. 



This simplifies the operation, allows the analysis 

 to be quickly performed, and admits of greater 

 accuracy when working with small samples. 



For the complete separation of copper from 

 bismuth, instead of the inconvenient t>rt ess of 

 fusion with bismuth sulphide, Edward Matthey 

 recommends as an effective method to fuse the 

 alloy, and at a temperature a little above its 

 melting point to add a small proportion of 

 sodium monosulphide. 



Ilydriodic aciu has been found by F. A.Gooch 

 and E. W. Banner a satisfactory 'substitute in 

 the separation of antimony from arsenic for the 

 ferrous chloride of Fischer s original method and 

 for the ferrous sulphate of the modification of 

 Classen and Ludwig. In these methods the chlo- 

 rides are reduced by means of ferrous chloride or 

 ferrous sulphate and ammonio-ferrous sulphate, 

 and the arsenic is volatilized by repeated dis- 

 tillations of the mixture with hydrochloric acid. 

 Chemical Synthesis. An effort toward the 

 solution of the complex problem of the synthesis 

 of the proteids has been made by P. SchQtzen. 

 The author had determined in previous researches 

 the terms resulting from the decomposition of 

 the proteic matters by hydratation under the in- 

 fluence of bases. The question arose whether, in 

 the inverse problem, the amides and amido-com- 

 pounds of a_ relatively simple constitution pro- 

 duced in the decomposition could be recombmed 

 so as to form complex bodies approaching the 

 proteic matters in constitution and the totality 

 of their chemical characters. The author solVed 

 this question in the affirmative, and succeeded, 

 by eliminating water and combining the ulti- 

 mate and crystallizable products derived from the 

 decomposition of albumen and fibrin under the 

 influence of baryta, in forming a nitrogenous 

 compound presenting great analogy with the 

 peptones, which may rank in the class of the 

 proteic compounds. 



The mineral hornblende has been artificially 

 reproduced in well-formed crystals by M. Kron- 

 tschoff. His process essentially consists in di- 

 gesting together in the presence of water, for a 

 long period of time, in a vacuum, the various 

 oxides contained in natural hornblende amphi- 

 boles. These ingredients were aqueous solutions 

 of silica, alumina, ferric oxide (all dialyzed), pure 

 ferrous hydrate, lime water, hydrate of magnesia, 

 and caustic soda and potash, in suitable propor- 

 tions. The mixture, which presented the ap- 

 pearance of a gelatinous mud, was heated in ex- 

 hausted and sealed flasks to a temperature of 

 550 C. for three months. At the end of this 

 time the mud had become much darker in color, 

 with numerous brilliant little crystals, almost 

 black, distributed through it. These, on exam- 

 ination, were found to consist of flattened prisms 

 identical in character with hornblende. 



The compound 3Ti,N,+TiCy t , which is oft- 

 en found in iron furnaces on smelting titanifer- 

 ous ores, may be formed, according to C. Lude- 

 king, of St. Louis, in the inner flame of a Bun sen 

 burner, which is made slightly luminous by a 

 proper regulation of the supply of air. On ac- 

 count of the characteristic appearance of this 

 compound, very small quantities of titanic acid 

 can DO quickly detected. The substance in ques- 

 tion is dissolved with a little sodium carbonate 



