130 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 

 I. Chemistry and Physics. 



1. On the Fusing points of Inorganic Salts. — The first results 

 of an investigation made by V. Meter and Riddle to determine 

 the fusing points of certain of the more refractory inorganic salts, 

 and thereby to ascertain what relation if any exists between these 

 points in the case of allied salts, have been recently published. 

 The salts thus far investigated are the chlorides, bromides, iodides 

 and sulphates of sodium and potassium. In order to measure 

 accurately the high temperatures in question, the authors made 

 use of the following method : The salt under examination was 

 placed in a large crucible of platinum and by means of a Perrot 

 furnace, was heated to a point considerably above that of fusion. 

 The crucible was then removed from the furnace and an air 

 thermometer, made of platinum and constructed on the compen- 

 sation principle, was inserted into the still melted salt. As soon 

 as solidification commenced, the temperature remained constant 

 for a considerable time during which the air in the thermometer 

 was displaced by hydrogen chloride gas. By measuring the 

 volume of this gas by absorption in water, the temperature could 

 be calculated. In this way it was found that the chloride, bro- 

 mide and iodide of sodium fuse at 851°, 727° and 650°, respec- 

 tively ; the corresponding salts of potassium melting at 766°, 

 715° and 623°. So that it appears that a lowering of the fusing 

 point is a consequence of an increase in the atomic mass, either 

 of the metal itself or of the halogen elements. Potassium oxide 

 moreover, fuses at 1045° and sodium oxide at 1098°. But in the 

 case of the sulphates, while the sodium salt melts at 843°, the 

 potassium salt melts at 1073°; a result which differs from the 

 law based on the behavior of the halogen compounds, although 

 it agrees with certain other differences already noticed between 

 the behavior of the oxy-salts of sodium and potassium and the 

 haloid salts of these metals. — Ber. Berl. Chem. Ges., xxvi, 2443, 

 November, 1893. G. f. b. 



2. On the Manocryometer. — A new instrument has been devised 

 by De Vissee for the purpose of determining the melting point 

 of a substance under pressure, which he calls a " manocryometer." 

 It consists of a stout glass vessel somewhat resembling Ostwald's 

 modification of the Sprengel density tube ; only the shorter capil- 

 lary tube is sealed off and the longer one is provided with two 

 small bulbs on the ascending portion, the horizontal part, which 

 is sealed at the end, being very long. The principal bulb is 

 filled with the substance to be experimented on, the lower part 

 of the capillary tube and the lower bulb are filled with mercury 

 and the rest of the capillary tube is filled with air which acts as 

 a manometer. The substance is heated to a temperature a little 

 above its melting point for half an hour and the pressure is then 



