New York AGRICULTURAL EXPERIMENT STATION. PALS 
largely provided with soda. It is, then, an acknowledged fact 
that soda cannot take the place of potash.” 
Oscar Loew’ states that: “The paramount importance of 
potassium salts for every living cell is firmly established. * * * 
These salts can never be replaced by lithium or sodium salts, 
but in certain fungi they may be replaced to a limited extent 
by rubidium or cesium salts. * * * The fact that many 
kinds of plants have been raised to perfection in the absence of 
sodium salts proves that the latter have no indispensable func- 
tions to perform in plant life. * * * Nevertheless, sodium 
salts may sometimes exert a beneficial action, and several observ- 
erg ascribe to them a promoting action in the ripening process 
of the Graminee.” * * * 
In regard to rubidium chloride he sums up some experiments 
as follows: “ These experiments proved that it is impossible to 
raise normal seed-bearing buckwheat plants when the potassium 
chloride in the culture solution is replaced by rubidium 
chloride, but on the other hand they left hardly any doubt that 
rubidium chloride can serve for certain physiological functions 
of which sodium chloride is utterly incapable. With rubidium 
chloride, buckwheat plants may reach a dry weight of even 
thirty-seven times that of the seeds, but with sodium chloride 
they seldom reach over five times. In a normally raised plant, 
however, the dry matter may be over six hundred times the 
weight of the seed.” 
A. Atterberg® carried on experiments with sodium. The fact 
that sodium is a common constituent of the ash of plants, led 
the author to test the question whether this element might not 
be capable of replacing in part other similar plant constituents, 
especially potash. Two series of experiments were made with 
black Tartarian oats, grown in pots filled with quartz sand and 
watered with nutritive solutions containing soluble plant food. 
Different amounts of potassium were replaced by like amounts 
"U. S. Dept. Agr., Div. of Veg. Phys. and Path. Bul. 18. 
‘Sodium as a Plant Nutrient. Deut. landw. Presse., 1881, p. 1035, ab- 
stracted Exp. Sta. Rec., 3 : 554. 
