CLXXVI. ECONOMIC ASPECT OF ARTESIAN BORING IN N.S.W. 
examination of the nature and amount of the latter. The limit 
usually given for drinking waters is 40 grains per gallon. 
‘Suppose that all, or nearly all of such matter were gypsum, 
however, the water would be still good for irrigation, and in fact, 
be preferable to purer water in most cases. In some good irriga- 
tion water in Texas and New Mexico, flowing from gypsum beds, 
as much as 160 grains per gallon are found ; but these waters are 
wholly unfit for drinking purposes. On the other hand, were a 
water proposed to be used for irrigation found to contain that 
amount of common or glauber salts, it would be difficult to use it 
without injury, save on the very highest land and for very tolerant 
crops. But even 40 grains per gallon of carbonate of soda would 
be at least equally dangerous, unless in conjunction with gypsum 
to transform the black into the white alkali. Even water con- 
taining 20 grains of the former, has, in some instances, caused 
serious trouble in three or four years. Each case must, there- 
fore be considered upon its merits, with due regad to all the sur- 
rounding circumstances.” 
GENERALLY. 
What I have written regarding this subject must, I fear, 
convey but an inadequate idea of what has been done in 
America. I have given simply isolated instances of the 
results from individual enterprises. These could be multi- 
plied one hundred fold and then no adequate idea would be | 
conveyed of the magnitude of what is being done, and the 
general eflort that is being made to supplement by irriga- 
tion the production under natural conditions. It will, of 
course, be gathered that the conditions obtaining in America 
are more favourable for irrigation than in this State. 
We have none of the snow-clad mountains and the extensive 
valleys and running streams that exists there, nor have we 
the teeming population and enormous market, nor their 
rail facilities. Wecan devise but few of the large gravita- 
tion schemes which are having such an enormous influence 
