BLOOD 69 



high power. How do red corpuscles differ in appearance 

 from the white corpuscles? Have they a nucleus? 



XLIII. — Study of Beef or Pig Blood. 



Apparatus. — Five-ounce bottles, fresh blood, egg beater, test 

 tubes, food-testing materials, constant temperature apparatus, com- 

 pound micr6scope, slides and cover glasses, distilled water, dialyzer. 



Directions. — ^A quart or more of fresh-drawn blood 

 should first be obtained from a butcher. Divide this among 

 the five-ounce bottles as follows : 



Bottle 1. Fill with fresh blood and cork so as to exclude 

 all air. 



Bottle 2. Fill two-thirds full and leave uncorked. 



Bottles 3, 4, and 5. Fill two-thirds full and cork. 



Place the remainder of the blood in a basin and whip 

 vigorously with an egg-beater or twigs. Take off the stringy 

 substance that collects on the beater, and wash it in water 

 until it has lost its red color. Put it in Bottle 6 and add 

 to it a little water. 



Pour the whipped blood into a suitable-sized bottle and 

 label it Bottle 7. Leave imcorked. 



A. Study of Coagulation or Clotting, Place Bottles 1 and 

 2 in ordinary room temperature. Examine frequently for 

 several days. In which bottle does the clot form quickest? 

 Does the absence of air in Bottle 1 have any effect on the 

 rate of clotting? 



Place Bottle 3 in a constant temperature of 36° C. and 

 pack Bottle 4 in ice. In which does the clot form quickest? 

 Does temperature affect the rate of clotting? 



Place Bottle 5 under the same conditions as 1 and 2 but 



