560 



WILLIAM S. STURGES AND LEO F. RETTGER 



observed in five different experiments by the conductivity, 

 bi'uret and Van Slyke methods. Number 4 was a physiological 

 saline solution suspension of the agar surface growths, while 

 the others were made up in distilled water. Two strains of 

 E. prodigiosus were used in these tests. 



The rate of autolysis was most rapid within the first twenty- 

 four hours, but required from ten to twenty days to be 

 practically completed. The biuret figures continued slightly 



VAN SLYKE DETERMINATIONS 



T 



t^ 



IS 20 2S <*3 3S to 

 Tin€ IN DAYS 



Chart 2. Erythrohacillus 

 prodigiosus 



Electrical conductivity is expressed 

 in reciprocal ohms. 



J lO IS ^O 2S JO JS 40 

 riMC IN DATS 



Chart 3. Eryihrobacillus 



prodigiosus 



The Van Slyke determinations are 

 recorded in the number of milligrams of 

 primary amino acids in 100 cc. of the 

 bacterial suspension. 



in the downward course even after the thirtieth day, whereas 

 the Van Slyke values attained their maximum by the tenth 

 day in two experiments, and by the twentieth day in a third. 

 The other two experiments were interrupted early. The biuret 

 and Van Slyke figures are in fairly close agreement; and both 

 are in a large measure supported by the results of the conduc- 

 tivity tests. The conductivity rose during the first seven to 



