CHEMICAL EQUILIBRIA 135 



5 cc. of different blood-sera are given here. The 

 quantity of the precipitate was with : 



Human blood . . . . . 0-31 cc. 



Blood from gorilla . .- . . 0-21 cc. 



orang-utang . . 0-13 cc. 



dog ape . 0-09 cc. 



Blood from half -apes (lemurides) gave no pre- 

 cipitate. These animals have very little relation- 

 ship with man. In the same manner the whales 

 (cetaceans) were shown to be in relation with the 

 hoofed animals (ungulata) and the reptiles with the 

 birds. About 1 6,000 measurements were carried out. 

 In a similar manner the plants have been examined, 

 especially by FRIEDENTHAL and MAGNUS. Their 

 experiments indicated, for instance, a relationship 

 between yeast and truffle. 



HAMBURGER has made some quantitative measure- 

 ments of the quantity of precipitate formed by cen- 

 trifuging it in a tube which ended in a very narrow 

 graduated tube i degree of the scale corresponded 

 to 0-4 cubic millimetres. These measurements were 

 given me for calculation. 



The simplest case was found with sheep serum 

 and the precipitin obtained by its injection in the 

 veins of a rabbit. Of the rabbit's serum containing 

 the precipitin always 0-4 cc. were mixed with a 

 variable quantity (A cc.) of the sheep serum diluted 

 in the proportion 1:49 with 0-9 per cent salt solution. 

 The quantity of precipitate P was measured (in 

 the unit 0-0004 cc.). At the side of the observed 

 quantities I have written calculated values obtained 

 from the formula 



