Q Art. 2.— Y". Shibata and T. Maruki : 



ill the form of fine brownish red needles containing 3 molecules 

 of water [Jorgensen, ibid., 445], This important salt was also 

 repeatedly recrystallised, until the estimation of cobalt in the 

 complex gave a quite satisfactory value. 



2) Mesotomisalion of Diammine-dinitro-oxalo-coball 

 Complex as Brucine Salt. 



To a saturated aqueous solution of l)arium diaramine-dinitro- 

 oxalo-cobaltiate, which was kept at about 40°C, finely pulverised 

 brucine sulphate (C23H2cN.04)28<>4H2, THoO was added in small 

 portions under constant agitation. The barium sulphate formed 

 was filtered ofï after the whole of the calculated amount of brucine 

 sulphate was added. 



As the filtrate became cooler, brown needles aggregating in a 

 radial form gradually began to appear here and there on the walls 

 of the vessel. After allowing the solution to stand over night at 

 the ordinary temperature, these crystals were gathered on a filter 

 as the first fraction. The mother liquor was then kept in a 

 vacuum over sulphuric acid, and the crystals, which separated out 

 from it, were gathered from time to time. In this way four 

 fractions in all were obtained. 



An estimation of cobalt and water with one of these fractions 



gave the following results: 



calc. for 

 obs [Co(NH,\(NO,\,C,0,]-H (CogKeN.O,), H^O 



Co =8-52% Co =8-59^ 



H20 = 2-72 " H.,0=2-63 » 



The four fractions gave the following values for their specific 

 rotations in an aqueous solution (0.3%, 10 cm): 



I [«]-'= -21.;3° 



III [«]?r=+27° 



IV [«]-g° =+'2y.:r 



The first fraction which consisted of the least soluble crystals 

 was found to be fairly unstable wlien dissolved in water, for on 



