( 259 ) 

 Tlie two ;il)()ve e(|iui1i(»]is |)a.>s jiow iiilo oiic : 



loil^^ =.--^,i'(l-2../) (18) 



''•1 ^<J e 



Iji lliis compleiuciitciiy compoöitioii wc lia\e a tlistiiict criterion, 

 wliether or no it is allowed to put u\ = a'.^ (i. c. /■ := 0). Further 

 the equation (18) Ciirnishes a simple means, wiien r may really be 

 put = 0, tor cdlcyhuliuj the qiiaiititi/ ji' fivni fJic con/jto.sition .t'/ of 

 the .solid j>hase at the eiitcctic point. 



If we find e.f;-. .c'l := 0,1, w^e may find by means of Tc = 500, 

 q, = 2400: 



hence 



If.??' had been 0,01, we should hav^e found with the same values 

 of Te and ^^ -. 



log 99 = — ,i' X 0,98, 

 5 



hence : 



125 



IÏ = /or/ 99 = 1,95. 



294 • 



It is seen, that a slight increase of /i' is able to depress the 



composition ,i\' of the solid phase at the eutectic point very strongly. 



This is of course in connection which the enormously strong decrease 



of the relation — with increasing ,i'. This relation was e.g. for T=r 7", 



a 



and great ^' represented bv - == ^^ (see § 3), which con- 



V-'V" 

 verges very quickly to 0. 



Chemistry. — "The phenomena of soUdijioUionand ti-dusformation 

 in the si/.stems NH, NO,, AgNO, 'and KNO,, AgNO,." By 

 Professor H. W. Bakhuis Roozeboom. 



(Communicated in the meeting of September !26, 1903.) 



Of the nitrates of univalent metals, those of Li, Na, Ag, NH^, K, Tl 

 have been studied more in detail as to tlieir mutual relations. It 

 has already been shown that the nitrates of the first three are very 

 prone to yield mixed crystals and tlie same takes place with the 

 last three. Li NO, and also Na NO, do not seem to form with the 



