146 BLOOD. 



mixture of the two fluids. In a similar manner add 



two volumes of (a?) to tube No. 4, and so on with the 



remainder. Empty, rinse and blot off fluid from the 

 pipette between each addition of proteid solution. 



Note carefully the lapse of time by your watch between 

 the moment of bringing the two fluids together and the 

 appearance of a cloud at their plane of junction. 



Test the solutions (c), (d\ and (e) with tests 5 and 6 for 

 proteids in the same way, being careful to use the same 

 quantity of reagent in each case, and determine their relative 

 sensitiveness. Construct a table of the results. 



Demonstrate the presence of a globulin in serum. 



To some serum which has been diluted with 2 volumes 

 of water add an equal quantity of saturated solution of 

 Am 2 SO 4 , the globulins will be ppd. Filter and care- 

 fully scrape the residue off the filter with a knife, and 

 mix it with some water, the pp will probably be 

 re-dissolved, enough neutral salt being present to do so. 

 If not, add a little 10 p - c - NaCl solution until it does. 



Test the filtrate for serum albumin (a) by boiling, and (b) 

 by saturating with Am, 2 SO 4 . 



11 Proteids in blood plasma. Coagulation experiments. 



Besides those already recognised in the serum, plasma 

 contains fibrinogen. 



(A) Salted plasma. 



Obtained by mixing blood as it flows from the blood-vessels 

 of an ox or sheep with half its volume of a saturated solution 

 of NaSO 4 , and then centrifuging. 



