138 



HEMOGLOBIN 



cross-section of the glass tube is of uniform composition. It would 

 not be imnatural to assume a stream line flow, with the possibility 

 that the fluid in the core was flowing more rapidly and was of different 

 composition to the layers situate in close contact to the glass. 



Some idea was formed of the nature of the flow by forcing two 

 fluids through the apparatus which by nature did not mix — coloured 

 water and paraffin. Experiments of this. character indicated a rotary 

 motion in the outer layers of the fluid, and indeed, bubbles visible 

 in the fluid suggested the question whether a core in the axis was 

 not moving towards the mixing chamber instead of away from it. 



/oO^Hh 



005 ' OiO •OI5 



TC/rtc in. Seconds 

 Fig. 41. 



• 020 



"Three independent tests were applied in order to answer this question: (1) to cause 

 alternately colourless and coloured fluid to pass down the observation tube, (2) to 

 compare spectroscopic readings taken through the centre of the tube, which would 

 therefore include the core, with those taken through the periphery of the tube, which 

 would not include the core, (3) to compare spectroscopic readings obtained on one 

 and the same reaction at slow and fast speeds. . . . Our conclusion is that all parts 

 of the fluid travel with the same velocity down the tube." 



The results of some tests in which the fluids passed at very different 

 rates along the observation tube are shown in Fig. 41: "the shaded 

 circles representing readings obtained with a slow linear flow (96 cm. 

 per sec.) and the blank circles representing readings obtained with a 

 fast rate of hnear flow (333 cm. per sec). The two reacting solutions 

 were in each of the experiments identical." 



