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Scientific Intelligence. 



stations distant two miles and eight miles from the conference 

 room of the General Electric Company in Berlin. Two instru- 

 ments were used, both of which were connected to the lightning 

 conductor in the neighborhood. One instrument syntonized with 

 that in the laboratory of Charlottenburg, the other with that 

 in the works at Ober Schonioeide. The greater part of Berlin 

 separated the conference room from one of the stations with 

 which successful messages were exchanged. — Nature, Dec. 27, 

 1900. J. t. 



10. The Telegraphone. — V. Poulsen discusses with figures his 

 very interesting invention. A small electromagnet connected 

 with a microphone is moved along on an iron wire while a message 

 is spoken into the microphone. Subsequently the microphone is 

 removed and a telephone, having been substituted for it, the 

 electromagnet not traversed by a current is again moved over 

 the iron wire and the message is reproduced. — Ann. der Physik y 

 No. 12, 1800, pp. 754-760. J. t. 



11. On the properties of Argon and its Companions. — In a paper 

 read before the Royal Society on November 13, by W. Ramsay 

 and M. W. Travees, after detailing the methods employed for 

 obtaining a supply of the gases associated with argon, the 

 authors give an interesting summary of their properties and with 

 this a statement in regard to their place in the periodic scheme. 

 We quote as follows : 



" That these are all monatomic gases was proved by deter- 

 mination of the ratio of their specific heats by Kundt's method ; 

 the physical properties which we have determined are the refrac- 

 tivities, the densities, the compressibilities at two temperatures, 

 and of argon, krypton and xenon the vapor-pressures and the 

 volumes of the liquids at their boiling points. The results are as 

 follows — 



Helium. Neon. Argon. Krypton. Xenon 

 Eefractivities (Air = 1)... 0*1238 0-2345 0-968 1-449 2-364 



Densities of gases (O = 16) 1-98 9-97 19-96 4088 64 



Boiling-points at 760 mm _ ? ? 86'9° 121-33° 163-9° 



abs. abs. abs. 



Critical temperatures ? below 68° 155-6° 2105° 287-7° 



abs. abs. abs. abs. 



Critical pressures ? ? 40-2 41-24 43*5 



meters meters meters 



Vapor-pressure ratio ? ? 0-0350 0-0467 0-0675 



Weight of 1 c.c. of liquid. ? 1-212 2*155 3-52 



? grams grams grams 



Molecular volumes ? ? 32-92 37'84 36-40 



The compressibilities of these gases also show interesting 

 features. They were measured at two temperatures — 11-2° and 

 237*3°; the value of PV for an ideal and perfect gas at 11*2° 

 is 17,710 meter-cubic centimeters, and at 237*3° to 31,800. This 

 is, of course, on the assumption that the product remains constant 

 whatever be the variation in pressure. Now with hydrogen at 

 11*2° C. the product increases with the rise of pressure; with 

 nitrogen, according to Amagat, it first decreases slightly and then 



