Carbonic-oxicle-liozmoglobin, &c, in the Magnetic Field. 507 



was rapidly centrifugalised, rapidly filtered into flasks surrounded by 

 ice and salt, and the haemoglobin caused to crystallise by the addition 

 of absolute alcohol under the prolonged influence of cold. After being 

 crystallised three times, the oxy-haemoglobin was collected on filters, 

 and the moist mass of microscopic crystals drained. The pasty crys- 

 talline mass was dried in vacuo over sulphuric acid at a temperature 

 which never exceeded 5° C. 



Behaviour in the Magnetic Field. — An irregular mass of three times 

 crystallised oxy-haemoglobin dried in vacuo, weighing 1*088 grammes, 

 and measuring 18 mm. in length, 13 mm. in depth, and 13 mm. in 

 breadth, was suspended by a couple of fibres of unspun silk between 

 the poles of the magnet, the distance between these being 20 mm. ; the 

 mass was made to rest in the axial position before the current was 

 passed through the coils. 



Three cells of an accumulator were employed ; on closing the key 

 the mass of haemoglobin instantly assumed the equatorial position. 

 The experiment was repeated with masses of haemoglobin prepared at 

 various times, and recrystallised from one to three times, and weighing 

 from - 5 to 2 grammes, and invariably they were found to be power- 

 fully diamagnetic. 



A specimen of oxy-haemoglobin of the horse, kindly prepared for me 

 under the direction of Professor Hofmeister in the Chemico-Physio- 

 logical Laboratory of the University of Strasburg, by the ammonium- 

 sulphate method, and which had been five times crystallised, proved to 

 be as powerfully diamagnetic as the oxy-haemoglobin prepared by 

 myself by Hoppe-Seyler's method. 



5. Carbonic-oxide-hcemoglobin is, like Oxy-hcemoglohin, strongly 

 Diamagnetic. 



Mode of Preparation. — The carbonic oxide-haemoglobin employed was 

 prepared by saturating a concentrated solution of twice crystallised 

 oxy-haemoglobin with pure CO, and then crystallising the CO com- 

 pound by the addition of absolute alcohol and exposure to a tempera- 

 ture of - 5°— 10° C. 



Behaviour in the Magnetic Field. — A nearly rectangular prismatic mass 

 of CO-haemoglobin which had been dried in vacuo, and which weighed 

 0*642 gramme, and of which the length was 17 mm., the breadth 

 6*5 mm., and the depth 13 mm., was brought into the axial position 

 between the poles of the electro-magnet, the distance between these 

 being 18 mm. On passing the current from three cells of an accumu- 

 lator through the coils of the electro-magnet the mass instantly 

 assumed the equatorial position. The experiment was repeated with 

 different specimens of CO-haemoglobin, and invariably with the same 

 result. 



