fAUT “i.] Center: Note on Reh or Alkali Soils and Saline Well loaders. 2f)7 
might be from 2 to 6 grains per gallon. If -well water is used, the accumulation 
is much greater, because it contains much more salt. In places where the water 
is sweet, the reh may bo about 6 to 15 grains per gallon ; whore it is salt, it may 
amount to more than 200 grains per gallon, as at various places on the Eailway 
Ljine between Lahore and ilooltau. Aii extraordinary instance is mentioned 
in the Aligarh Report of a reh soil tried by the most energetic measures with¬ 
out effect. An analysis of this soil would probably have proved that the ele¬ 
ments of the soil itself wore in such a state of decomposition that most of the 
measures em 2 ffoyed assisted the process. Again, water running off a saline 
field must necessarily dissolve a yior’tion of its salt, and if it be allowed to run 
into another and dry, that salt will bo deposited. The agency of wind ajjjjeai's 
to be a slight and very variable one. There is no doubt that wind blowing over 
a saline country and raising dust transports saline particles. Travellor.s over the 
alkali jjlateaus of the Rocky Mountains are familiar with the irritation caused 
to the eyes by this mode of transport. All these, however, are of secondary 
importance. The main points to bear in mind are, that there are several factors 
causing production and accumulation, and others loading to the removal of 
earth salts. Of the former ther-o is first the soil itself. This is always generat¬ 
ing them, and in certain cases its materials so readily undergo decomposition 
that 2 >erhap.s even artificial moans may fail to cure the o\dl. The next cliicf 
factor is the water arsed in irrigation. This always contains reh salts,_tiro 
river and canal water in small amount, but the tvoII water often in enormous 
qrrantities. In addition, the irrigation water may not only deposit it.s salt in the 
soil, but it causes further ^wodnetion in the, soil itself. Another cause is the 
sirccial condition in which the subsoil water lies within the reach of capillary 
action from the surface, which may give rise to an inexhaustible supply. The 
factors concerned in the removal are, first, permeability of the soil, which may 
allow the salts to bo washed down to the undergi-ound water. If this have a 
ready outlet, they are removed ; if not, there will be a saline ground water; but 
the surface may show no accumulation if the water table is deep. If, however 
the ground-water is a very short distance from the sui’face, there may bo a pro¬ 
fuse efflorescence under the usiral conditions of dryness of the atmosphere and heat. 
The second cause of removal is coiiions rainfall. If the rainfall is copious, it may 
wash away jrar’t of the salts, and this is one of the I’oasons that in rainy regions 
alkali is rare. If it is slight and only moistens the soil without scouring it, there 
will be a continuous ^rroduction and accumulation on the surface, ex'cept when 
the soil is porous and allows it to bo carried down to the ground-water. The 
third means of removal is by vegetation, which annually takes up its necessary 
portion of salts and assimilates them. It is frequently observed that in culti¬ 
vated spots the reh is kejrt under, while the uncultivated ground around may be 
covered with it. In connection with this, it is to be remarked that for land 2>lants 
potash salts are necessary, but it is doubted whether soda salts are essential, ex¬ 
cept in the case of Salsolre, &c., which grow in soda soils. This may have some¬ 
thing to say to the barrenness of our soda reh soils. Another factor to be noticed 
is the effect of shade produced by vegetation, which prevents the excessive eva 2 )o- 
ration which brings the salt to the surface. It thus remains more diffused 
