50 



(kit'i'iuiiicd lor iibrohlasls j^row ii in llu- ciilliu(.'s lo which 

 media llu' (Hlfcronl Irnclions were addcfl nnd the j^rowth- 

 indox ('(unparcd willi the amoiiiil of iiili-o-^cnous substances 

 ill the same IVaelions. 



Table .'>. 



TECHNIQUE. 



Mostly experiments of adsorption were made with bhxxl 

 coal as adsorbent. The concentration of the adsorbent used 

 was 10 o/o and this was foimtl most satisfactoi'v to worlv 

 with. 



Fresh embryonic tissue juice fi'om about S days old 

 chicken embryos was prepared in the usual way. 1,5 cc. 

 of this was carefully measured in sei'ies of test lubes. 1,5 cc. 

 of a standard buffer solution ol dilfei-enl Fh. wei'e addedi 

 to the juice in order lo give llie solutions certain different 

 hydrogen ion concentrations. The method is the same as 

 has been described before (F i s c h e r) J»"). After the buf- 

 fer solution has been added and the desired Ph. obtained,! 

 0,3 gram of blood coal was added. 11 is obvious, that the 

 procedures were carried out strictly ase|)tically. with sterile 

 solutions and glasswares. As control for llu' adsorption ex- 

 periment another series of the same extract was mixed 

 with exactly the same buffer solutions. l)ut witli the ex- 



