266 



Transactions of the Canadian Institute. 



[Vol. VII. 



the paper might be seen readily at any time without disturbing the 

 plates. One could hardly say that atmospheric conditions had much to 

 do, under these circumstances, with giving the water between the plates 

 any quality, either acid or alkaline. The strips of paper all turned 

 slightly blue, showing that the water and glass had probably something 

 to do with the change. This change took place long before the water 

 had evaporated, showing that the evaporating down to dryness was no 

 important factor, though, so far as is known to the writer, this is the only 

 reason assigned for the change. 



FIG. 6. 

 F, is a flask enclosing a leaf and kept in position by a support. P, a plug ot cotton in the flask. 

 R & B, red and blue litmus paper strips. 



Experiment to test the acid or alkaline quality of distilled water 

 which has been allowed to stand upon a living leaf for some time. 

 Plant used, Helianthus. Plant placed under a bell-jar. 



I. — December i^th, igoo. 



3 strips red litmus paper placed on g-lass slide under jar and moistened, 

 became blue in 24 hours ; dry. 



2 strips red litmus paper placed on the inside of jar ; moist ; no chang^e. 



3 strips (red) placed upon leaves touching- jar ; moist ; turned blue. 



3 .strips (red) placed upon leaves not touching jar; dry ; no change. 



II — December 16th. Observations made in 24 hours ; reddened litmus paper used. 



4 strips on glass slide, moist, under jar . . .Reaction, bluish. 



4 " touching inside surface of jar, moist. " 3 red ; i (dry) blue. 



4 " on leaf touching jar, moist " bluish. 



4 " in beaker of dist. water under jar... " red. 



4 " on slide, moist, under beaker not 



with plant " bluish. 



4 " on inside inoist beaker inverted " bluish (dry). 



4 " on under side of leaf, moist " blue. 



