CLXX. ECONOMIC ASPECT OF ARTESIAN BORING IN N.S.W. 
States gallon contains 58°328 grains, while that of this 
country, the Imperial gallon, contains 70°000 grains. There- 
fore, we cannot accurately compare the two analyses 
without reducing them to the same base. Now our chemists 
Messrs. Guthrie and Mingaye, who have carried out our 
analyses and who have written much upon this subject, 
have placed the limit of safety upon water which contains 
from 30 to 60 grains per Imperial gallon of alkaline car- 
bonates, the land containing practically no alkali; while 
in America the limit runs as high—the land also charged 
with alkali—as 100 grains per American gallon. The 
shallowness of soil has been given some prominence for 
the reason that it has been found to be the cause of failure 
in many instances. 
Professor Hilgard’s paper, which I have already referred 
to, should be read by all iaterested in artesian well irriga- 
tion. It is entitled, ‘‘ The use of Saline and Alkaline 
Waters in Irrigation,’”’ and was read before the Irrigation 
Congress at Lincoln and Sacramento in 1897, and is as 
follows :— 
“The vital importance of irrigation in the arid regions, and the 
consequent high value of irrigation water, offer a great temptation 
towards the use of waters containing relatively large amounts of 
saline ingredients, which from the very nature of the case are of 
very frequent occurrence. ‘The origin of this saline contamination 
is, of course, the same as that of the alkali lands themselves. Such 
waters may, in the majority of cases, be considered as the leachings 
of alkali lands. ‘That the occurrence of the latter is essentially 
the result of a deficient rainfall, is insufficient in amount to carry 
the salts naturally formed in the weathering of all soils into the 
country drainage, as currently happens in the region of summer 
rains, has been sufficiently explained in former publications of this 
Station, which have also set forth the means that may be used 
towards the reclamation of alkali lands for profitable culture. 
