114 
SEVENTH ANNUAL MEETING OF THE 
trees, and hope in the course of three or four years to know a 
little more about its value than at present. 
TOBACCO STEMS. 
During the last few years there have been thousands of tons 
of tobacco stems used in Florida with, 1 believe, general satis¬ 
faction when applied occasionally. A continuous use of them 
tends to make coarse fruit and soft wood. The}' seem to be 
an excellent tonic for the soil. 
GYPSUM. 
While it contains no plant food of itself, it is valuable. It 
has the power to catch the ammonia that comes down with 
the rain or is freed from decaying vegetable matter and hold 
it till wanted by the plant. Sometimes it has given as good 
results as a complete fertilizer on this account. But it will 
not do to depend on its doing this. 
GAS LIME. 
We hear of gas lime being spoken of as a splendid fertil¬ 
izer. On this subject I will read what Prof. Caldwell, of Cor¬ 
nell University, says about it: 
“Gas lime is composed chiefly of carbonate of lime and vary¬ 
ing quantities of sulphate of lime (or ordinary land plaster)* 
sulphite of lime, sulphide of lime, and more or less unchanged 
lime. The sulphite and sulphide are harmful to vegetation* 
especially the latter; but on exposure of the gas lime for a 
considerable time they become changed to the useful sulphate- 
The carbonate is of little value, and only the sulphate and 
the unchanged lime can be counted on as of any use. 
“I do not consider the material as of much value for fertil¬ 
izing purposes; for after due exposure to the air, to render the 
sulphide and sulphite harmless, the unchanged lime will also,, 
in this time, be converted to carbonate, so that only the sul¬ 
phate is left to be useful; and if I were going to use land plas¬ 
ter, I would prefer to buy it outright and know what I have. 
“As an insecticide its use would be dangerous, because of 
its effect on the plant itself, unless it has been well aired, and 
for its usefulness in this respect, after having been thus aired, 
it would be the same as a mixture of plaster and chalk.” 
As gas lime can be had for 2 cents per bushel at the gas 
works at Baltimore, I should think that the farmers there 
would use it all up if there was the virtue m it claimed. 
HOW TO COMPOUND FERTILIZER. 
The compounding of fertilizers lias been held up as a deep 
mystery; which has taken years to find out, etc., while the 
