EXPERIMENTS WITH GLOBIN 325 



be the haematin part of the haemoglobin molecule which 

 has any function in causing proliferation; it must be 

 the globin part if it is either of them. 



In the first instance we tried the effect of haemo- 

 globin on blood-cells. Jellies were made which con- 

 tained 1 cc. (10 units) of alkali solution, and after they 

 had been boiled various quantities of a saturated solution 

 of crystalline haemoglobin were added before the jellies 

 cooled too much for them to set on a slide. But haemo- 

 globin never induced divisions in lymphocytes or 

 leucocytes in the experimental ten minutes. Nor did 

 it excite amoeboid movements in them. 



We next made a saturated solution of haemoglobin 

 and then boiled it, thereby decomposing it and pre- 

 cipitating the haematin. The filtrate is a straw-coloured 

 liquid when it is dilute. It was evaporated down by 

 prolonged boiling, and at the saturation point, which 

 is about 4 per cent, the solution becomes a deep red 

 colour. On evaporation to dryness, a sticky residue 

 remained. Very little is known (about globin. For 

 years it was thought to be a globulin, but this has 

 been shown not to be the case. Globin is a histone 

 a protein which is not precipitated by boiling. In the 

 dry state it is a glutinous mass of a deep brick-red 

 colour, and it has a characteristic sweet smell some- 

 thing like licorice. If it is very dry, globin can be 

 ground into a brown powder. It is at all times ex- 

 tremely hygroscopic, and therefore if it is not kept in 

 solution it must be placed either in a desiccator or in 

 sealed tubes. If it is kept in solution and exposed 

 to the air, it rapidly decomposes owing to putrefaction, 



