lxxx GENERAL SUMMARY OF SCIENTIFIC AND 



flames, gives experimental evidence to prove (A) that a 

 flame may be rendered non-luminous (a) by cooling it, (b) 

 by diluting it with an indifferent gas, the temperature of 

 combustion not being increased thereby, and (c) by energetic 

 oxidation of the luminous matter; and (B) that the lumi- 

 nosity may be restored (a) by heating the flame, (b) by raising 

 the temperature of its combustion, as by heating the gases 

 before they burn, and (c) by diluting the oxygen with an in- 

 different gas. In a subsequent paper he asserts, contrary to 

 the view expressed by Blochmann, that it is to the cooling 

 of the gas by the burner itself, or by some object introduced 

 into it, that the space between the flame and the burner or 

 the object is due. 



Laspeyres has proposed a more perfect apparatus for the 

 direct estimation of water in minerals, etc., consisting of a 

 series of calcium-chloride tubes, through which a current of 

 dry air is passed, in which the substance is heated. The 

 chloride of calcium used is dried at 150 to 200 C. 



Vierordt has suggested the use of his quantitative spec- 

 trum-analysis method in volumetric assay, and gives experi- 

 ments which show its very great advantages. 



Volhard has aided analytical processes by describing a 

 new swimmer for burettes, a new form of ammonia appara- 

 tus, and a new calcium-chloride tube for organic analysis. 



Bach has described some simple devices for laboratory 

 apparatus, viz., a water-blast, a wash -bottle with constant 

 stream, and a gas cock. 



Griffin describes his new form of portable gas furnace, in 

 which a pound of cast iron can be melted in thirty-five min- 

 utes, and the new method of supporting crucibles in it. 



Godeffroy has discovered that caesium salts give precipi- 

 tates readily with quite a number of metallic chlorides, thus 

 making the reaction with antimonous chloride previously ob- 

 served by him quite general. The reaction he has observed 

 with chlorides of the following metals, all the precipitates 

 being ciwstalline : iron, bismuth, zinc, cadmium, mercury, 

 copper, manganese, and nickel. Rubidium salts behave sim- 

 ilarly. 



Kilson lias made a series of experiments on the salts (par- 

 ticularly the selenites) of the rarer earths, with a view to 

 determine the equivalents of the contained elements. He 



