152 



BLOOD. 



W 



13 Spectroscopical examination of the blood. Use a 

 small direct vision spectroscope suitably supported. Keeping 

 the red end to the left the spectrum is to be sharply 



focussed by adjusting 

 the draw -tube. The 

 slit is to be reduced 

 by means of the milled 

 head at the other end 

 of the instrument, short 

 of seeing the horizontal 

 lines caused by the 

 irregularities of the 

 jaws of the slit. Burn 

 biborate of soda in the 

 flame to get the Na 

 line. 



Draw a chart of the 

 spectrum by marking 

 the position of the sod- 

 ium line and the limits 

 of the colours by vertical 

 lines, continuing them 

 on the paper to serve as 

 guides in plotting below 

 each other the follow- 

 ing absorption spectra. 



FIG. 16. Direct vision spectroscope S on a wooden Examine the blood 

 stand. P wedge-shaped bottle for blood solutions. 

 G gas. W platinum wire with a borax bead for the solutions in wedged- 



shaped bottles 1 . 



Solution of blood. Make a 2 1XC - solution of ox or sheep's 

 blood in water. Or you may add one or two drops of your 



'Made for the author by the York Glass Company. 



