190 



per cent, could be resisted for two months, with no apparent in- 

 jury to the pitcher. The growth of the young pitchers containing 

 such a solution was equal, so far as it could be measured, to that 

 of pitchers containing water. Solutions of the various strengths 

 were tested with hot Fehling solution after they had been in the 

 pitchers from three to seven days. The contents of each pitcher 

 gave a reddish precipitate of copper oxide, indicating the produc- 

 tion of invert sugar. A heavy reduction of Fehling solution also 

 occurred spontaneously without heating although water from the 

 pitchers did not behave in this way. 



As checks for this experiment, Fehling solution, as well as 

 Fehling solution with an equal quantity of the stock sugar solu- 

 tion was boiled, but neither gave an indication of reduction. 



Starcli. — Starch paste was placed in the pitchers and allowed 

 to remain three or four days, in one case as long as thirteen days, 

 when it was removed and tested in the usual way with Fehling 

 solution. The result indicated that a reducing compound, pre- 

 sumably sugar, had been formed, the exact nature of which was 

 not determined however. When Fehling solution was added to 

 starch paste from the pitchers iviihout boiling, no reduction oc- 

 curred, so that the reducing power of the contents was not so 

 marked as in the case of the cane sugar. Tested with iodine, a 

 few blue granules indicated that not all the starch had been hy- 

 drated. Toluol sufficient to forma thin film over the top of the 

 fluid in the pitcher was added in some cases but the reduction was 

 the same as in the case of pitchers to which no antiseptic had 

 been added. From this it may be concluded that the change 

 from starch to reducing substance (sugar ?) is due to an enzyme 

 secreted by the cells of the pitcher. There were no indications 

 of fermentation in the pitchers with toluolized contents. 



As checks in the experiments on the action of the pitchers 

 upon starch paste, Fehling solution was tested by boiling ; tap- 

 water and Fehling solution were boiled together ; and tap-water 

 which had been in the pitchers for the same length of time and 

 under the same conditions as the starch paste, was boiled with 

 Fehling solution ; also, tap-water to which toluol had been added, 

 and which had been allowed to stand in the pitchers the same 



