63 KEPORT 1871. 



atmosplieric air ? "With baryta the problem can be solved veiy perfectly, if not 

 economically. Another process is that of Tessier de Mothay, in which the man- 

 ganate of potassium is decomposed by a current of superheated steam, and after- 

 wards revived by being heated in a current of air. A company has lately been 

 formed in New York to apply this process to the production of a brilliant house- 

 light. A compound Argaud burner is used, having a double row of apertures ; the 

 inner row is supplied with oxj'gen, the outer with coal-gas or other combustible. 

 The applications of pure oxygen, if it could be prepared cheaply, woidd be very 

 numerous ; and few discoveries would inore amply reward the inventor. Among 

 other uses it might be applied to the production of ozone free from nitric acid by 

 the action of the electiical discharge, and to the introduction of that singular body, 

 in an efficient form, into the arts as a bleaching and oxidizing agent. Tessier de 

 Mothay has also proposed to prepare hydrogen gas on the large scale by heating 

 hydrate of lime with anthracite. 



We learn from the history of metallurgy that the valuable alloy which copper 

 forms vnth zinc was known and applied long before zinc itself was discovered. 

 Nearly the same remark may be made at present with regard to manganese and its 

 alloys. The metal is difficult to obtain, and has not in the pure state been applied 

 to any useful purpose ; but its alloys with copper and other metals have been pre- 

 pared, and some of them are likely to be of gi-eat value. The alloy with zinc and 

 copper is used as a substitute for german silver, and possesses some advantages 

 over it. Not less important is the alloy of iron and manganese prepared according 

 to the process of Henderson, by reducing in a Siemens's fm-nace a mixture of car- 

 bonate of manganese and oxide of iron. It contains from 20 to 30 per cent, of 

 manganese, and will doubtless replace to a large extent the spiegeleisen now used 

 in the manufacture of Bessemer steel. 



The classical researches of Eoscoe have made us acquainted for the first time 

 with metallic vanadium. Berzelius obtained brilliant scales, which he supposed to 

 be the metal, by heating an oxychloride in ammonia ; but they have proved to be 

 a nitride. Roscoe prepared the nietal, by reducing its chloride in a current of 

 hydrogen, as a light grey powder, with a metallic lustre under the microscoi)e. It 

 has a remarkable affinity both for nitrogen and silicon. Like phosphorus, it is a 

 pentad, and the vanadates correspond in composition to the phosphates, but differ 

 in the order of stability at ordinary temperatures, the soluble tribasic salts being 

 less stable than the tetrabasic compounds. 



Sainte-Claire DeviUe, in continuation of his researches on dissociation, has ex- 

 amined the conditions under which the vapom* of water is decomposed by metallic 

 iron. The iron, maintained at a constant temperature, but var^-ing in different 

 experiments from 150° C. to 1600° C, was exposed to the action of vapour of 

 water of known tension. It was found that for a given temperature the iron con- 

 tinued to oxidize, till the tension of the hydrogen formed reached an invariable 

 value. In these experiments, as Deville remarks, iron behaves as if it emitted a 

 vapour (hydrogen), obeying the laws of hygrometiy. An interesting set of expe- 

 riments has been made by Lothian BeU on the power possessed by spongy metallic 

 iron of splitting iip carbonic oxide into carbon and carbonic acid, the former being 

 deposited in the iron. A minute quantity of oxide of iron is always formed in this 

 reaction. 



The fine researches of Graham on the colloidal state have received an interesting 

 extension by Keynolds's discovery of a new group of colloid bodies. A solution 

 of mercuric chloride is added to a mixture of -acetone and a dilute solution of 

 potassium hydrate till the precipitate which at first appears is redissolved, and the 

 clear liquid poured upon a dialyzer which floated upon water. The compo.sition 

 of the colloid body thus obtained in the anhydrous state was found to be 

 ((0113)2 CO), Hg3 O3. The hydrate is regarded by Reynolds as a feeble acid, even 

 more readily decomposed than alkaline silicates. A solution containing only five 

 per cent, forms a firm jelly when heated to 50° C. Analogous compounds were 

 formed with the higher members of the fatty ketone series. In the same direc- 

 tion are the researches of Marcet on blood, which he finds to be a strictly colloid 

 fluid containing a small proportion of diffusible salts. 



In organic chemistry the labours of chemists have been of late largely directed 



