51 



Tomato Juices. 



Four tomato juices were tried, all from fiuits of thrift}' hot-house 

 plants of one variety (Lorillard). The fruits were ])i('ked and sorted 

 into groups as follows: (1) Stock 331, fruits red and ripe, with a tine 

 odor, excellent for the table; (2) stock 332, fruits full grown and yel- 

 lowish-green, i. e., connnencing to ri})en; (3) stock 333. fruits entirely 

 green, hut nearly or (piite full grown; (4) stock 334, small green fruits, 

 one-twentieth to one-fourth grown. The juices were obtained by 

 pul})ing the fi-uits and extractmg under pressure. These fluids were 

 then filtered, steamed, filtered, tilled into tubes, and sterilized ])y steam- 

 ing 1<> minutes on 2 consecutive days and 15 minutes on the* fourth day. 

 Each juice was carefully titrated for acidity and sugar content. Starch 

 was abundant in the green fruits, but there was very little in the yel- 

 lowish-green fruits and none whatever in the ripe fruits. Grape sugar 

 was most abundant in the yellowish-green fruits. The acidity of the 

 yellowish-green and of the ripe fruits was nearlv the same, but 

 undoubtedly they contained more than one acid, and the proportions 

 were probably different. Each of these stocks was inoculated with at 

 least one-half cubic millimeter of the vellow slime of Ps. hyacinthl 

 from a coconut culture 7 days old, a check inoculation (which grew 

 promptly) ])eing made into alkaline beef broth. All of the tubes were 

 kept together in feeble diffused light at room temperatures which 

 ranged from 22° to 34° C. (mostly 25° to 28°) during the first 25 days, 

 and after that 29° to 35° C, and occasionally for a few hours as high 

 as 37" (^Washington summer heat). The results obtained are given 

 below: 



(1) Stock 331. No growth (85 days). The acidity of the stock was +64, and the 

 sugar content was sucli that 2.5 c. c. were required to reduce 5.c. c. of the standard 

 sohition of CuSOj oH^O in Soxhlet's solution. 



(2) Stock :«2. No growth (35 days). The acidity of this stock was ^m, and the 

 sugar content was such that only 1.8 c. c. were required to reduce 5 c. c. of the 

 standard solution of CuSO^ 5H.^0. 



(3) Stock 333. No growth (35 days). The acidity of this stock was +55, and the 

 sugar content was such that 3.7 c. c. were required to reduce 5 c. c. of the standard 

 solution of CuSO^ 5H.,(). 



(4) Stock 334. No growth (35 days). The acidity of this stock was +59, and the 

 sugar content was such that 2.2 c. c. were required to reduce 5 c. c. of the standard 

 solution of CuSOi 5H2O. 



The acidity here recorded marks tln^ first perceptible trace of change 



N 

 of color on adding -rnNaOH drop by drop to 5 c. c. of the juice in 50 



c. c. of water plus 1 c. c. of the standard alcoholic solution of phenol- 

 phthalein. More alkali was recjuired to produce a ))right pink, and, if 

 this be taken as the standard color, then the readings would be, respec- 

 tively, + 74, +75, +65, and +72. Still more alkali was n^quired to 



