

52 



produce a red which could not be made deeper. The readings when 

 addition of more alkali did not deepen the color were, respectively, 

 +111, +88, +81, and +93. 



In each case these figures are the average of three titrations at room 

 temperatures. Titrated boiling hot, each of the fluids required con- 

 siderably more alkali. 



Ps. ca^npestris, Ps. j^^i-seoli., Bacillus amylovorus^ and B. olece also 

 refused to grow in these juices. On the contrary, stocks 333 and 334 

 were well clouded by Ps. stewarti on the fifth day, and 331 became 

 well clouded some time between the eighth and fifteenth day. In each 

 of these 3 fluids this organism made a copious and prolonged growth, 

 but it refused to grow in 33:2, although this contained more sugar than 

 the other stocks; and even when reinoculated copioush" from 331, after 

 the latter had become well clouded, it remained clear. It is probable, 

 therefore, that the limit of toleration of Ps. steioarti for the acids of 

 the tomato lies between +61 and +68. 



Hyacinth Broth. 



Perhaps the most interesting result of all was obtained with hyacinth 

 broth. This was made from 13 rather small ])ulbs of a single-flowered 

 white variet}^ of Hyacinthus orien talis. The bulbs had been kept 

 in a closet in the laboratory all winter and had lost some water, but 

 were not shriveled. In March the plateaus were removed (the most 

 alkaline part of the bulbs) and the remainders w^ere pulped and an 

 effort made to extract the juice. Only a very sticky slime oozed 

 through the bag, and this would not flow. I then added 100 c. c. of 

 distilled water and squeezed out as much juice as possible inider an 

 iron press. An endeavor was made to pass the fluid through a Cham- 

 berland filter, but it would not go through with a pressure of 25 

 pounds per square inch. The fluid was then thoroughh^ steamed and 

 filled into test tubes after filtering out a very copious white coagulum, 

 consisting principally of nitrogenous substances, starch, and raphides. 

 There resulted a hazy, yellow, acid fluid, which never precipitated 

 entire!}^ clear. Titrated with caustic soda and phenolphthalein, 1 c. c. 



N . 



exactlv balanced 0.28 c. c. of Tr^NaOH (first trace of color), and con- 

 sequently the acidity was +^8 of Fuller's scale. Pushed far enough 

 to give a bright pink, the reading was +10. This fluid was moder- 

 ately acid to neutral litmus paper. Four clean, well-plugged tubes, 

 each containing 10 c. c. of this fluid, were inoculated with a large loop 

 of Ps, hyaclntld from an alkaline beef-broth culture 2 days old, which 

 broth was inoculated from a solid cultore and had been cloudy for 21 

 hours. The tubes were kept in a dark place at room temperatures 

 very suitable for growth, viz, 19"^ to 25° C. 



