[Vol. 2 



788 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



coagulum either came to the top or settled to the bottom of 

 the vessel— if to the top, it was usually very much aggregated 

 and little difficulty was experienced in the filtering, if to the 

 bottom, it was generally in a very finely divided condition and 

 unless care was exercised in the decantation of the super- 

 natant liquid the pores of the filter soon became clogged, re- 

 sulting in extremely slow filtration. Time was therefore given 

 for a complete settling out (15 minutes to half an hour sufficed) 

 and all the clear fluid filtered off before the coagulum reached 

 the filter paper. 



A homogeneous diffusion of the precipitate was made by 

 placing the filter paper with the attached coagulum in a known 

 volume of distilled water. The paper could soon be removed 

 without loss of material, and the weight of the original fresh 

 or dry tissue represented by an aliquot portion of the solu- 

 tion easily reckoned. If the precipitate were not required im- 

 mediately, it was dried on a filter paper at room temperature 

 and stored in stoppered jars. In none of the experiments 

 was the enzyme material purified further. 



When dissolved in water, the precipitates behaved differ- 

 ently. Some, especially those where much slime had been 

 noticed in the extraction, gave an extremely viscous suspen- 

 sion, others a suspension of low viscosity. In Laminaria and 

 Chondrus, where the extract had been quite viscous and slimy, 

 the protein was caught up in the precipitated slime in such a 

 way as to make the freeing of it practically impossible. The 

 precipitate in these cases was very large and when diffused 

 in water gave a suspension difficult to handle. Rhodymenia, 

 Ceramium, and Enter omorpha, on the other hand, gave a 

 finely divided precipitate that produced no viscosity. 



Glassware, antiseptics, solutions, etc. — With few exceptions, 

 the various experiments were set up in 125 cc. Erlenmeyer 

 flasks. All glassware was thoroughly cleaned with strong 

 soap and then with chromic-sulphuric cleaning mixture, after 

 which it was rinsed several times with tap and distilled water. 



Solutions were made up from either Merck's or Kahlbaum's 

 ' ' guarantiert ' ' chemicals. 



