16 



proKeiithtjtiKitmis tissue. The quantitj- ab- 

 sorbed Tvas enormous, thus the common 

 cabbage, in 1'2 hours, gives out from its leaves 

 15 to 25 oz. of water. A sun flower 3ft. 

 high and. weighing Httle over 31bs., in sum- 

 mer gave from ' 16 to 20oz. in 12 hours. 

 Schleiden saj^s the fluid is transmitted from 

 cell to cell of the prosencln'matous tissue. 

 He thought also that the prosench\-matous 

 tissue was the means of its diffusion. To 

 detei-miue this, experiments had been made. 

 Hoftmann put roots in a solution of ferro- 

 cyanide of potash, made sections which he 

 exposed to a salt of lime, and obtained a 

 Prussian blue in the prosenchymatous 

 tissue. A vegetable color, the juice of the 

 berries of a Ph^-tolacca was also tried, and 

 gave a crimson color in the same tissues. 

 At first he had himself tried similar experi- 

 ments with cuttings of plants, in water tinged 

 with carmine, and as in the case of a wall- 

 flower, both stems and leaveswcre penetrated 

 by the fluid, but as this might have been by 

 capillary attraction, he had tried to get 

 carmine taken up by the root, and in the 

 course of a few days had found the color in 

 the stem, the leaf-stalks, and leaves, the 

 flower-stalk, and the floral envelopes. He had 

 also tried the feiTO-cyanide, but not knowing 

 the strength to apply had killed the plants. 

 Tlie ascending fluid was unfit for the economy 

 of the plant, and had to be elaborated, both 

 to build up the plant and to produce the 

 secretions : this great change was made in the 

 leaf where exhalation took place, and in which 

 were the stomata, most nimierous in those 



