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quantity of it in rain water on the western and eastern coasts of 
Scotland is 11.9 and 12.6 mgrm; at greater distance from the sea 
it is less, but that river water represents a concentration to one-third 
of the rainfall. Bopierre had found at Nantes, likewise not far from 
the sea, during 12 months, an average of 14 mgrm of chloride of 
sodium per liter of rain water. Our Dutch down water, which also 
may be considered as rain water concentrated to about one-third, 
contains 40 till 70 mgrm of chloride of sodium, according to its 
being taken farther from or nearer to the sea. Direct mixing 
with sea water is, as has long been known, totally excluded here; 
the part of the rain water sinking in the dunes flows partly to the 
sea, partly landward. The rain water may therefore have a quantity 
of about 13 till 23 mgrm of sodium chloride per liter there. 
At greater distance from the sea the quantity of sodium chloride 
in the rain water is much smaller. At Ootacamund, 120 KM. from the 
coast, in South India, it contains only 0.4 mgrm per liter. The evapo- 
rating quotient there is 5, according to Murray’), so that on this 
account the river water can still have a quantity of 2 mgrm of sodium 
chloride per liter. Muntz?) found in low regions, at Bergerac 
(Dordogne), at a distance of 136 KM. from the coast, on an average 
2,50 mgrm, and at Joinville-le-Pont near Paris, 190 KM. from 
the sea, on an average 7.60 mgrm, on the Pic du Midi (2877 M. 
above the sea) however only 0.34 mgrm of chloride of sodium per 
liter of rain water. According to these data an estimate of 0.4 mgrm 
of sodium chloride in the rain water falling on the drainage area 
of the Meuse, is certainly not too high. Now considering that the 
evaporating-quotient for the area of the Meuse is 2.6, according to 
SPRING and Prost, we find that 1 mgrm at least of the sodium 
is owing to the rain. According to what is known of the domestic 
consumption of salt and other human sources supplying sodium to 
the river we probably have to add to this at least an equal quantity. 
So we arrive at the conclusion that certainly not more than 1,5 mgr. 
of the sodium, found by the analyses, is due to chemical denudation, 
and that this amount is perhaps not at all combined with chlorine. 
Still we did not charge our account for the possible source of 
„fossil sea water’, indicated by Sterry Hunt, O. FrsHeR and 
especially JOHANNES WALTHHR®), but which is wholly uncontrollable. 
The Elbe carries, in absolute quantities, more than twice as much 
Mi Tas e.g p-+ 7B. 
*) A. Munaz, Sur la répartition du sel marin suivant les altitudes. Comptes rendus 
de l'Académie des Sciences. T. 112 (1891), p. 447—449. 
*) JonaNNes WanrHer. Das Gesetz der Wüstenbildung, p. 143 sqq. Berlin 1900, 
