PAET J..] 
MeiNicoft; The lieh Suih of Ujjjjer Intlia. 
373 
extracting the nitre. Samples have from time to time been forwarded to this 
office, and these were found to contain from 85 to 70 per cent, of common salt. 
It wonld certainly he possible and not very difficult to obtain a rather impure 
alimentary salt by rough crystallization processes, not only from the saltpetre earth, 
but also from suitable kinds of reh. 
The Eeh Soils of Uppee Ixdia, hy H. B. Medlicott, M.A., Geological 
Survey of India. 
For some time I have intended to publish in the Survey Eecords a notice 
of the saline efflorescence known as reh, which has been, and will continue 
indefinitely to be, a subject of the gravest concern to those intere.sted in the wel¬ 
fare of Xorth-Western India. The preceding paper, contributed by Mr. Center, 
removes the only grounds of hesitation in the matter—as to the adequate 
illustration of the chemical aspects of the case. The facts of this nature aEeady 
ascertained by myself and others from the area affected were, indeed, sufficient to 
e.stablish the case before a jury of experts, and it would have been easy to adduce 
further illustration from analogous conditions elsewhere ; but the men who have 
to deal with the matter practically are very much the reverse of exjterts, scarcely 
even believers, and it is of the greatest importance that the most tangible part 
of the evidence, the hard facts verifiable by the balance, should be set before 
them from the very ground which they have to treat. This has been done in a 
very satisfactory manner by ilr. Center. It only remains for me to supple¬ 
ment his paper regarding some points which it touches on but slightly. The 
question is truly a geological one, as embracing all the conditions of a complex 
operation now at work in producing a change in the whole region affected. 
This has been the difficulty throughout—to induce an apprehension of the 
situation: that the evil to be encountered is not a fixed obstruction of assignable 
dimensions and position, but the present active array of natural causes bent upon 
fulfilling the effects due to conditions that have supervened. In such a case our 
best efforts may be no more than palliative, unles.s indirectly, by modifying those 
conditions, we can mitigate the action of the prime causes. 
2. From times far earlier than the date of British occupation, there have been 
large patches of reh-affected ground in various parts of the Upper Provinces. 
They are known as usar (sterile) and halar (saline) land. As the contention 
sustained in this and the preceding paper is, that this salt (as such) was not an 
original constituent of the deposits in which it now occurs, it would be interesting 
to find any mention of the itsar lands in remote records of those districts; but it 
is not at all unlikely that some of them may be of very ancient origin, from the 
historical point of view. What has recently (within the la.st 30 years) brought 
the subject into such prominence was the rapid local extension of reh efflorescence 
in connection with the great irrigation canals that have been constructed in Upper 
India. Shortly after my arrival at Eoorkee (Eurki), then the head-quarters of 
irrigation, I was consulted about this plague of salts; not, indeed, as a geologist, 
