69 



sugar bouillons stimulated growth. No gas was formed. The growth 

 in each was typical for Ps. hyacinthi. 



In 2 of the 3 tubes of galactose Ps. hyacinthi refused to grow, and in 

 the third clouding did not appear until after the seventh day. On the 

 ninth da}^ the fluid in the bowl and outer two-thirds of the U was 

 feebly clouded. After a time there was an abundant 3'ellow growth 

 on the operr end of the tuVje, but the closed end remained clear 

 throughout the experiment. The fluid, as we have seen, was neutral 

 to phenolphthalein (strongly alkaline to litmus) on the start. It was 

 still strongly alkaline to litmus on the ninth day; on the fifteenth day 

 it was moderatel}^ alkaline. On the twenty-third da}^ it was neutral 

 to litmus or nearh^ so, but so was an uninoculated tube. On the 

 thirtieth day the fluid was distinctly acid, even to the purplish red 

 paper. No gas was produced. The cloudy fluid was now pipetted 

 from the open end of the bulb into a clean test tube and reduced b}'^ 

 boiling to one-third its original volume. Moistened litmus paper was 

 reddened in the vapors which first came oft' (CO.j::). Afterwards there 

 was no reddening of the litmus paper in the steam and the concentrated 

 fluid was more acid than before. 



The fact that the organism failed to grow in two of the tubes and 

 was retarded in the third was attributed to the effect of a soluble 

 brown substance which appeared in the tubes as a result of the 3 

 steamings which followed the addition of the galactose. 



(2) Absolute ethyl alcohol was also pipetted into 4 tubes of the same 

 stock. Two of the tubes received 2^ per cent and two 5 per cent of 

 this alcohol. Each tube was then inoculated with two 3 mm. loops 

 from fluid cultures 13 days old (tubes 1 and 2, January 20, 1899). 

 This experiment was suggested by the results obtained with Sharp 

 and Dohme's litmus solution in milk. In one of the 5 per cent alco- 

 hols the organism failed to grow. In the other 3 tubes clouding 

 occurred on the fifth to the seventh day; i. e., growth was retarded very 

 decidedly. The tubes never became heavily clouded; growth ceased 

 early and the closed end remained clear (30 days). The fluid was 

 plainly alkaline to litmus at the beginning and on the ninth and the 

 fifteenth days. On the latter date the appearance of the cultures was 

 that of simple toleration of the alcohol rather than of any use of it for 

 growth. The alkalinity in one of the 2^ per cent tubes on the fifteenth 

 day was rather feeble; i. e., much less than in an uninoculated tube or 

 than in inoculated tubes of the simple bouillon. On the twenty-third 

 day the fluid had settled clear and was feebly acid to litmus. On the 

 thirtieth day the fluid (in each tube) was clear and was distinctly acid 

 to both the litnuis papers. No gas had formed. The precipitate was 

 distinctly yellow but scanty; i. e., there was only about one-twentieth 

 to one-fiftieth as nuich as in the tu])es of simple bouillon and about 

 one one-hundredth as much as in the tubes of grape sugar and cane 



