400 Scientific Intelligence. 



In a subsequent paper the authors describe the diphenyl deriva- 

 tive of the new base which they call iodonium hydroxide. On 

 treating iodosobenzene, which has been exposed in a thin layer 

 to sunlight for a few days or better, has been heated for some 

 hours to 60°, with moist silver oxide, the diphenyl derivative of 

 the new base is produced. It appears that the iodosobenzene 

 C 6 HJO is oxidized to C 6 H 5 IO„ ; and the reaction is C 6 H 6 .IO + 

 C G H 6 .I0 2 + Ag OH=Ag I0 3 + HO.I.(C 6 H 6 ) 2 . If a mixture of 

 these iodized benzenes in proper proportion be mixed with silver 

 oxide and agitated for three hours and then filtered, the clear 

 solution on adding potassium iodide yields over ninety per cent 

 of the theoretical quantity of crystals of diphenyl-iodonium 

 iodide. The salts of the iodonium bases strongly resemble those 

 of silver, lead and thallium. The diphenyl iodide forms large 

 and beautifully grouped acicular crystals fusing at l75°-6° and 

 passing into the polymeric mono-iodo-benzene C 6 H 5 I. The aque- 

 ous solution of the free base is very stable, is strongly alkaline 

 and absorbs carbon dioxide. Sodium sulphide precipitates a yel- 

 low and ammonium sulphide an orange sulphide. — Ber. JBerl. 

 Chem. Ges., xxvii, 426, 502, Feb. Mch., 1894. g. f. b. 



5. Diminution of the force of gravity icith the height, deter- 

 mined by weighing. — Franz Richarz and Otto Krigar Menzel 

 communicate some preliminary results obtained, from a very com- 

 plete experimental station established in the fortifications at Span- 

 dau. Each of the two pans of a balance were provided with rods 2 

 meters long ; upon these rods other scale pans were hung. A direct 

 determination of the difference of weight in these scale pans was 

 made. Futhermore a mass of lead weighing 100,000 kilograms 

 was placed in the space between the two vertical pans. On the 

 upper pan the force of the earth and the attraction of the iead mass 

 act in the same direction. On the lower pan they act in opposite 

 directions. A complete description is given of the installation of 

 the apparatus in a room of the fortress. Unusual precautions 

 were taken to avoid changes of temperature. Only at short inter- 

 vals, however, could concordant observations be taken. A discus- 

 sion of the method of weighing is given. The difference of weight 

 obtained was g u — <7 =0 , 5 6523 m/sec 2 while the calculated value 

 was g u — ( ^ =0 , 6 697 m/sec 2 . 



The observed value was thus smaller than the calculated value. 

 The authors are now in a condition to carry the investigation to 

 a successful conclusion. — Ann. der Physik und Chemie, pp. 559- 

 583, No. 3, 1894. J. T. 



6. A laic of candle flames. — P. Glan, after a careful examina- 

 tion of the illuminating power of candle flames in comparison with 

 their dimensions concludes that equal portions of the flame of dif- 

 ferent candles radiate the same amount of light. The value of the 

 lighting power of a cubic centimeter of a candle flame can be ex- 

 pressed in terms of # 7035 cm flame volume of a Walratkerze. — 

 Ann. der Physik ic?id Chemie, pp. 564-590, No. 3, 1894. j. t. 



