( 552 ) 



Tjpf lis fii-sl (il)sei'vo llirit ilic (liclcrtric fonstant of livdraziiie is 

 oiily surpassed hy those of live oilier liquids and is deeidedl}^ larger 



tliau Ihal of Nil,. AVe have namely: 



hydrocyaiiie aeid 95 aeetouitrile 40 



hydmgeji pei'oxide 93 iiitrobeiizene 36.5 



water 82 iiielhylalcohol 32.5 



formic acid 57 ammonia 22 fat — 34°) 



jiilrcMuelhaiie 56.5 pyridin 20 

 hydia/.ijie 53 



The peculiar |)roperties of hydrazine (its very hygroscopic nature 

 and liability to oxidation by atmosi>heric oxygen) demand great 

 precautions in its preparation. It took place, according to the method 

 already described 'j, by treatment of the so-called hydrate with 

 barium oxide and distillation in an atmos|)here of hydrogen. 



The heating with barium oxide and subse<[uent distillation were 

 thrice i-epeated and the base was tinally collected in six diiferent 

 tractions in pipetle-shape(l tubes in the manner {treviously described. 

 During the last dislillation the base had i>een only in contact \vith 

 piirided, dry hydi-ogen. 



Apart from the properties of hydrazine mentioned, the high cost 

 of the material \\ as a factor which in our experiments lia<l to be 

 taken into account. A special a|)pniat us (see illustration) was, therefore 

 cKjislructcd w liich ;Kliiiitt('(l of w orkin^- with a small <|uantity of the base 



B (about 5.5 c.c.) and through 



which pure, dvy nitrogen^) 

 could i)e [tassed, whilst 

 thi'ough the exit tube for 

 the gas the weighed portions 

 of the different salts could 

 be introduced. 



()ji account of the some- 

 what limited ({uantity of 

 the base at disposal we 

 could not, as is customary 

 in the determination of the 

 condacti\'e power of solu- 

 '^ M tions, start with the largest 



concentration and succes- 

 sively dilute this by adding 

 the solvent, but the reverse 

 was to be done. 



1) 1. c. p. 175, 



') We take the opportunity to call attention to the fact that platinised electrodes 



