47 



culllvalcd in ])iirc plasiiiM wifhoiil addition of any I'xlracl 

 but dihilod with Ringer solution to conipcnsalt' the dilu- 

 tion of the experimental culture. 



The cultures to whicii the globulin IVactiou was added, 

 showed slightly more growth than (\u\ the control cultures 

 in j)ure plasma. In other words, only a small portion of the 

 growth j)rom()ting sul)slances I'emained in the globulin 

 fraction. 



The albumins wei'e obtained by saturation with yVm- 

 monium sulphate of the filtrate from the globulins and the 

 ammonium sulphate removed l)y dialyzation. This fraction 

 did not show any activating power at all. Similar results 

 were obtained by C a r r e 1 for the serum albumins. 



It is probable that the chemical procedures are rather 

 rough and have a destroying effect on the growth promo- 

 ting substances. It seems, however, that the active substan- 

 ces are to be found in the globulin fraction. This was also 

 expected from the experinu'uts made by Carrel and E b c- 

 ling 1"-;. They found, that the active substances of serum, 

 could be detected in the globulin fraction. 



It was important to find other methods of ju'ecipitalion 

 being less aggressive to the growth promoting substances. 

 By using carbondioxide as a precipitant for the preparation 

 of the globulins, we found a method more suitaljle. 



3. Carbondioxide precipiialion of the globulins. 



The extract was diluted from four to twenty times with 

 redistilled water. Kept at 0" C.. C(L was allowed to trickle 

 through the solution for about half an hour. The [)recipitate 

 obtained after centrifuging was washed in water saturated 

 with COj at C. After being washed that way, it was im- 

 mediately after dissolved in Ringer solution and brought 

 up to the original volume, and the hydrogen ion concen- 

 tration adjusted to about Ph. 7. The filtrate from the glo- 

 bulins was evaporated at 40 °C. to its original volume. 

 This fraction contains the albumins. 



