nv K. C. OHKY. 309 



glohin. There is another interest attached to this experiment. 

 As was pointed out, the supernatant fluid was acid towards 

 phenolphtlialein, althougli neutral to methyl orange. 



Of the supernatant fluid, 250cc. required 1 -Occ. N/iONajCOg 

 to render the solution distinctly alkaline to meth3'l orange. Of 

 the same solution, 250cc required 3"3cc. N/10 NaOH to produce 

 the first pink colour with phenolphthalein. It is clear, therefore, 

 that organic acids are produced in the solution during the 

 decomposition of haemoglobin with sulphuric acid. This fact has 

 been pointed out before by other observers. 



Haematin was completely removed from the solution before 

 titration, by l)oiling till precipitated and filtering. 



Since the total volume of the fluid used in this experiment was 

 1650cc., and this volume contained 80cc. N/10, H0SO4, every 

 lOOcc. contain 0'024 gram of sulphuric acid, which is practicallv 

 the quantity recommended by Lawrow. This experiment shows, 

 therefore, that more sulphuric acid is necessary to precipitate 

 globin from ox-blood than from the haemoglobin of the horse. 



It should be mentioned that these experiments, in which an 

 exact quantity of sulphuric acid was used, were carried out after 

 I had previously ascertained, by analysis of the precipitated 

 globin, that the substance contained a considerable amount of 

 chemically combined sulphuric acid, a conclusion which was 

 arrived at independent of Lawrow's work. At that time, the 

 globin was j )recipitated in the presence of a larger amount of 

 sulphuric acid, 2cc. pei- litre, for 50cc. of 50% solution of ox-blood. 



Experiment 2,. — Oh the nmght of globin obtainable from ox-blood. 



Method. — The Lawrow method was modified by the use of a 

 larger excess of sulphuric acid. The details of the operation were 

 also different, and arc rlescribed below. 



Defibrinated ox-blood was used in all the experiments, the 

 oxygen capacity of the blood being previously determined. In 

 order to avoid any loss, the operation of centrifuging the corpus- 

 cles and washing away the serum was carried out on a innnber 

 of small lots of blood w-hich were subsequently luiited. Twelve 

 lots of defibiinated blood, 50cc., were carefully measiucd, and 



