512 Bulletin 167 



tested was added to the mixture which was again brought to a 

 boil and maintained at gentle ebullition for 2 minutes. It was 

 then removed from the hot plate and transferred to a porcelain 

 evaporating dish and left to settle for a few minutes. The liquid 

 was decanted and the bottom of the dish examined for precipitated 

 copper. The following table shows the results obtained. The 

 presence of precipitated copper is indicated by the sign -)-, and 

 its absence by the sign — . Where only a very minute precipitate 

 was obtained it is indicated by the word "trace." 



The reaction in scries A and B was in general characteristic. 

 In series C, numbers 1 and 4 were characteristic, number 2 was 

 nearly so, while numbers 3 and 6 gave a muddy solution with an 

 uncharacteristic color and, in addition to the copper oxid, the pre- 

 cipitate contained a brown, light weight, flocculent material. 



Cultures upon potato slants 4 days old were washed with 

 distilled water, the washings were filtered and tested for reducing 

 sugars with Fehling's solution with negative results. 



Effect of germicides.— The germicidal effect of formaldehyde 

 and of phenol were tested in broth cultures of the organism by 

 adding definite known quantities of these germicides to tubes of 

 sterile medium and then inoculating with a 2 mm. loop of young 

 broth culture. 



Formaldehyde. — As a basis r\.r this work a guaranteed 40 

 formaldehyde was employed. < me cc. of the solution was added 



