( •'>M ) 



Chemistry. ■' TIn' (■oiKlnctirc jiim-i-r of liii<lr<i:im' <iii<l i>r' snlishdicc^; 



(lissolrcil thci-clii." l)V Prof. Kknst ( 'oiiKN and l'i of. (.'. A. I .ouKV 

 i)K Bri'yn. (CV)niiHuiiit'iite(t hv Prof. C A. Lourv J)k 1>ki vn). 

 (Comimiiiicalod in the incdini^' of l'\.'l)rnary :2S, 1903). 



The iiivestigalion of (l»e comluclive })(»\vei- onum-aqueous solutions 

 lias ot' late yeai's boon known to liavc an inci-easinii; siuiiilicanco and 

 particularly so on aocount of tlio ini|K)i-tanl rosult that the laws aixl 

 i-ulos applyinii,' to a(|uoous solutions do not a]»i)oai' to apply in the 

 case of other solvents. Apart tVoni nielhyl and ethyl alcohol (the 

 constitution of which does not differ much from the type water) 

 suli)hurdioxide, ammonia (NHJ, formic acid, liydroeyanic acid, pyri- 

 dine, some niti'iles, hydi-ogen jioroxido and others have hoon studied 

 as such ^). 



The physical j)roperties of fi-eo hydrazine ^) N^H^ although still 

 incompletely known, might load us to sui)pose that this liipiid would 

 manifest a sti-ong ionising |)ower. In the lii-st place, like water, the 

 lower alcohols and acids, it ])ossessos an abnormally high i)oiling 

 point. This is obxious if this point (about 113° at 760 m.m.) is 

 compared with of annnonia ( — 34°), difference of 147°, aiul if one 

 considers that the diffoi'ence between the i)oiling points of ('II., and 

 C,H„ is decidedly le.ss (80°); f his fact as well as the high critical 

 temperature of (at least) 3(S0° point to an association of the N.,H^ 

 molecules. The solubility of several alkali salts in hydrazine has also 

 been shown to be vei-y considerable allhoiigh less ihan in water. 

 Anothei' existing obserxalion points to the fact that hydi-azine inay, 

 like ammonic take the [)lace of water of crystallisation '). And finally, 

 the dielectric constant of hydrazine, which Prof. P. Dkidk ((üessen) 

 had the kindness to determine at our rocpiest, has liirned out lo be 

 rather high, namely, 53 at 22°. It is now a kiu)W]i fact thai there 

 exists a certain although sometimes remote parallelism between the 

 dissociating |)ower of a li([uid on th(^ one hand and the association 

 of its molecules, the solvent power and the dielectric conslant on 

 the other hand. As according to the experiments of Ki;\nki.in and 

 Kr.ms and of Capv licpiofiod ammonia is an ioni.sing solvent, this 

 might also be expected in the case of hydrazine. From the oxperimenls') 

 [)resently to be described it will be seen that such is ihe case. 



1) Compare Joxes, Am. Cli. .1. 25. 'I'.Vl. K AiH.KNiJF.r..:, J. Phys. Cliem. 5. 330. 

 Walde.\ and Centnekszwku, Z. pliys. Cli. 39. :)li, T):.; c. by J. Th.ube, Cli.-in. 

 Zt. 26. 1071. (Ilt02). 



2) Lobby de Bucyn, Recucil iles Truvaux C]iinii(|iios ilos Pays-Bas. 15. 174. 



=0 Ibid. 170. 



^) Some pielimiiiaiy (i».lermiiiatioii:< wcie already lu^de in ISOIi. I. c. 170. 



