456 Scientific Intelligence. 



ordinary temperature. Then an excess of hydrochloric acid is 

 added, and the excess of iodine is determined at once by means of 

 sodium thiosulphate solution, with the use of starch as an indica- 

 tor. The final result corresponds to the equation, 



HSCN4 3l, + 4H,0 = H,SO^ + 6HI + HCK 

 The experimental results obtained were extremely accurate, 

 and the author advises the standardization of volumetric thio- 

 cyanate solutions by this method. — Beriehte^ xxxv, 2766. h. l. w. 



3. Iodine Pentafluoride. — This compound w^as prepared, pro- 

 bably in an impure condition, by Gore in 1871 and by Maclvor 

 in 1875, by the action of iodine upon silver fluoride. Moissan 

 bas now^ prepared it by allowing fluorine gas to act upon iodine. 

 Combination takes place with evolution of heat and the product 

 is a colorless liquid boiling without decomposition at 97°, and 

 solidifying at 8°. In the solid state it resembles camphor. The 

 liquid fumes in the air, and when poured into water it is decom- 

 posed without violence into hydrofluoric and iodic acids accord- 

 ing to the equation, 



2IF^ -f oH^ = 1,0^ + lOHF. 

 The fluoride possesses great chemical activity ; most elementary 

 bodies decompose it, and it enters into reactions with a great 

 number of compound substances. When its vapor is heated to 

 the neighborhood of 500° it decomposes, showing the color of 

 iodine vapor. — Comptes Rendiis, cxxxv, 563. h. l. w. 



4. Separation of Manganese from Magnesium^ Zinc and 

 Alurninxtm. — To effect these separations Dietrich and Hassel 

 precipitate the manganese as higher oxide in dilate sulphuric or 

 nitric acid solution b}^ means of ammoninm persulphate. For 

 quantities of manganese corresponding usually to "1^ MnO or 

 less they used 5^° of dilute sulphuric acid (1 : 10) and 15-20" of 

 a ten per cent solution of ammonium persulphate. In the separa- 

 tion from magnesium the total volume of the liquid was 150-200'='^, 

 while in the other cases, where the quantities of zinc and alu- 

 minum oxides present were about the same as that of the man- 

 ganese Oxide, a volume of 400-500°° was used. The precipita- 

 tions were made in solutions heated upon the water-buth and 

 frequently stirred, and the heating was continued for about two 

 hours in order to decompose the excess of ammonium persulphate. 

 The manganese precipitates, after filtering and washing, were 

 ignited directly, and MugO^ was weighed. The test analyses 

 gave very satisfactory results. It seems probable that this 

 method will find useful application in mineral and rock analyses, 

 in which, by the usual methods, the separation especially of man- 

 ganese and aluminum presents some difliculties. — Berichte, xxxv, 

 3266. H. L. w. 



5. Plasticity and Adhesiveiiess of Glass at Ordinary Tem- 

 p>eratures. — That glass possesses a certain amount of plasticity 

 when not heated has been known for a long time, but it has not 

 been shown definite!}^ that this plasticitj^ is sufficient to produce 

 adhesion similar to the weldinsr of metals. Piccaed has now 



