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cipally common salt, with a trace of gypsum and 
sulphate of magnesia : the remaining 16 parts were 
vegetable matter. 
The solutions of the saline substances were used 
twice a week, in the quantity of two ounces, on 
spots of grass and corn, sufficiently remote from 
each other to prevent any interference of results. 
The substances tried were super -carbonate , sulphate , 
acetate , nitrate , and muriate of potassa ; sulphate 
of soda , sulphate , nitrate , muriate , and carbonate 
of ammonia . I found that in all cases when the 
quantity of the salt equalled part of the weight 
of the water, the effects were injurious; but least 
so in the instances of the carbonate, sulphate, and 
muriate of ammonia. When the quantities of the 
salts were ^ part of the solution, the effects were 
different. The plants watered with the solutions 
of the sulphates grew just in the same manner as 
similar plants watered with rain water. Those 
acted on by the solution of nitre, acetate, and super- 
carbonate of potassa, and muriate of ammonia, grew 
rather better. Those treated with the solution of 
carbonate of ammonia grew most luxuriantly of all. 
This last result is what might be expected, for 
carbonate of ammonia consists of carbon, hydro- 
gene, azote, and oxygene. There was, however, 
another result which I had not anticipated ; the 
plants watered with solution of nitrate of ammonia 
did not grow better than those watered with rain 
water. The solution reddened litmus paper ; and 
probably the free acid exerted a prejudicial effect, 
and interfered with the result. 
Soot doubtless owes a part of its efficacy to the 
