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640 The Philippine Journal of Science 1922 
under the bell jar. He found a greater percentage of total ash 
in the leaves of the plants grown in the open than in those of 
the one plant under the shaded jar. This experiment is of little 
or no value, as only the leaves were analyzed and only very few 
plants were grown. It is interesting to note, however, that he 
assumed the difference in the ash content ‘to be due to the dif- 
ference in total transpiration. 
According to Hasselbring (10) Fittbogen expressed in 1871 an 
idea similar to that of Lawes. 
Sorauer, (8, 4) in 1878-1880, grew various species of plants such 
as barley, pea, lupine, and others in humid and dry conditions 
and found in general a greater amount of dry substance and a 
higher percentage of ash under dry conditions than under humid. 
Hasselbring (10) again tells us that in 1883 Hellriegel considered 
there was no relationship between transpiration and the pro- 
duction of dry matter, and that Kohl in 1886, on anatomica} 
grounds, assumed that a rapidly transpiring plant receives, 
by means of the transpiration stream, far greater amounts of 
mineral nutrients than a plant with lower transpiration. 
Wollny, (5) in 1898, grew barley, vetch, lucerne, and flax under 
dry, moist, and medium conditions. In general he found greater 
absolute amounts of fresh and dry substances and a higher per- 
centage of ash under humid conditions than under dry atmos- 
phere. Pfeffer(6) remarks that these results of Wollny were 
probably due to the necessary protection against transpiration 
in dry air retarding the gaseous exchange, and thus also carbon 
dioxide assimilation and growth. After citing the results of 
the experiment of Schloesing already referred to in this review, 
Pfeffer expressed the belief that transpiration favors the ab- 
sorption of the constituents of the ash. 
In 1905 Livingston,(7) experimenting with wheat seedlings, 
published the conclusion that total transpiration of wheat plants 
grown in various media is as good a criterion for comparing the 
relative growth in these media as is the weight of the plants. 
Jost,(8) in 1907, without presenting any data, states in his 
text that plants which transpire freely are far richer in ash 
than those transpiring feebly. He appears to be convinced that 
transpiration greatly helps in the absorption from the soil of 
large quantities of salts. 
Thatcher,(9) 1913, performed some analyses of wheat grains 
to determine the effect of sunlight on their composition. The 
plants were grown under canvas cover and in the open. In seven 
of nine cases he found very significantly higher percentage of 
