52 CLINICAL BACTERIOLOGY AND 



and, before it has become too cool to lose its plasticity, bend 

 it towards the body of the tube up to about an angle of 

 25 to 30 degrees (Fig. 26). 



The stem should now be burned through at a short 



£ 



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% 



Fig. 25. — Wright's Blood-Capsule. 



distance from the bend, the complete capsule being the 

 shape of Fig. 27. 



To collect blood in this capsule, care should be taken to 

 see both ends are open. If the blood is being taken from 

 a small superficial vein in the horse, after opening the vein 



Fig. 26. — Weight's Blood-Capsule. 



with a lancet, the bent end should be placed in the blood- 

 drop, and by capillary attraction the blood will siphon into 

 the tube, while the air will recede from the straight end. 

 When sufficient blood has been collected, heat the straight 

 end in a small flame, and seal it up. As the imprisoned hot 



Fig. 27. — Wright's Blood-Capsule. 



air at this end cools, it will contract, and the blood will be 

 withdrawn from the bent end, which in turn may be sealed. 

 The blood will now clot and separate out the serum. This 

 squeezing out of the serum may be hastened by centri. 



