1902.] 



and Physical Properties of Hcemoglobin. 



81 



parent to allow the ultra-violet spectrum of cadmium to be photo- 

 graphed, present no absorption bands corresponding either to the 14th 

 or the 17th cadmium lines. The absorption band observed by Soret 

 in correspondence with line 14 is, therefore, not due to the blood 

 colouring matter, but to some other organic constituent present in 

 the blood. 



(2.) Behaviour of Oxy-hcemoglobin and CO-hcemoglobin in the Magnetic Field. 

 The Intense Ferro-magnetic Properties of Hcematin and Hcemin. 



Having referred to his researches communicated to the Eoyal Society, 

 in June, 1901, and illustrated the main facts by actual demonstrations, 

 the author discusses (1) observations on the influence of tempera- 

 ture on the behaviour of oxy-hsemoglobin in the magnetic field : (2) 

 observations on the ferro-magnetism of the ferro-albuminates. 



(3.) The Specific Conductivity of Solutions of Oxy-hcemoglobin. 



The author next examines the question of the specific conductivity 

 of solutions of pure oxy-hsemoglobin. 



In this research he has worked exclusively with the haemoglobin of 

 the horse, and, following substantially the method of preparation which 

 in Zinoffsky's well-known investigation yielded the purest product, he 

 succeeded in obtaining crystallised oxy-hsemoglobin of remarkable purity, 

 the ash of which consisted solely of oxide of iron with an indetermin- 

 able trace of P 2 5 and contained no trace of chlorine. He employed 

 oxy-hsemoglobin three times recrystallised, and in addition to the 

 thorough washing by decantation with 20 per cent, alcohol after each 

 successive crystallisation, he treated the ultimate product many 

 successive times with large quantities of pure distilled water having 

 a conductivity which never exceeded 10 -6 x 2*5, the washed haemo- 

 globin being separated by the aid of the centrifuge. The solutions 

 which formed the subject of investigation were made by dissolving 

 the mass of moist haemoglobin crystals in pure distilled water of 

 35° C, and cooling the solution thus obtained as rapidly as possible. 



In his determination of specific conductivities, the author employed 

 the method of Kohlrausch. The bridge was Kohlrausch's metre bridge, 

 of which the platinum-iridium wire was 3 m. in length. This bridge is 

 furnished with resistances of 1, 10, 100, and 1000 ohms, the precision 

 of which had been kindly determined some years ago for the author 

 by Dr. Glazebrook, F.E.S. The resistance vessels employed were 

 those known after the name of Arrhenius, and the temperature was 

 kept constant by immersing them in one of Ostwald's thermostats 

 furnished with a windmill stirrer. 



After a laborious investigation on this branch of the subject, the 

 author has arrived at the following conclusions : — 



G 2 



