CLXXIi. KHCONOMIC ASPECT OF ARTESIAN BORING IN N.S.W. 
and among the reasons assigned for so doing has sometimes been 
the unquestioned fact that luxuriant vegetation is found growing 
along the shores or margin of lakes and streams to which the 
warning applied. It therefore, seems necessary to explain why 
this is so, and that it is perfectly consistent with the correctness 
of the objections made to the use of the water. 
“As a matter of fact, but few waters naturally occurring—such 
as the ocean, Great Salt Lake, Mono Lake, and others—are 
sufficiently strong to prevent or destroy vegetation of which they 
bathe the roots, so long as their saline strength is not increased 
and concentrated by evaporation. According to the investigations 
made in Europe early in the century, it takes over 1,000 grains of 
common salt per gallon to prevent the growing of most culture 
plants in water ; a few will tolerate as much as 1,300. According 
to our own experience, plants will tolerate more than twice as much 
of glauber salt (sulphate of soda) as they will of common salt, but 
carbonate of soda is nearly three times more injurious than com- 
mon salt to the growth of plants. As these three salts—sulphate, 
carbonate, and chloride of sodium —constitute in varying propor- 
tions the bulk of what is known as ‘“‘black” and “white” akali, it 
will be readily understood that, according to the nature of these 
salts, and of others occasionally accompanying them, the tolerance 
of plants for them may vary greatly for the same total amounts 
of soluble salts contained in the water. For this reason alone, 
then, it is not easy to give figures or percentages stating exactly 
how much alkali, in soil or water, a plant will tolerate. A series 
of elaborate culture tests on alkali that have been made during 
the last five or six years have shewn approximately the tolerance 
of some of the more important culture plants for alkali salts. 
Some of these figures have been given in former reports, while 
others are given for the first time in the present one, and these 
experiments and investigations are being continued under the 
numerous varying conditions that may determine tolerance or 
intolerance. 
“Among these varying conditions apart from the composition — 
of the alkali salts above referred to, the most important appears 
