GYPSUM. 319 



They declared that gypsnm was not only incompetent to replace 

 schlot or the refuse of their pans, as had been proposed, but that it 

 was injurious ; schlot was the only veal improver, the stimulant of 

 stimulants, for which there was no substitute. But it turned out by 

 and by, that the schlot of the salt-pan was found to be neither more 

 nor less than sulphate of lime, than gypsum — the article that was 

 not only inefficient, but injurious. These gentlemen were afraid 

 that the use of gypsum extending, they would want a market for 

 their refuse. 



The use of gypsum once introduced, extended rapidly in P^rance, 

 particularly around Paris, whence it crossed the Atlantic, and the 

 fiehls of North America were actually manured with the produce of 

 the quarries of Montmartre. The lately cleared lands of America 

 abound in humus, and the plants indigenous there were most bene- 

 ficially acted on by gypsum, which really produced remarkable 

 effects ; in both the new and the old world, its power, as one of the 

 most useful auxiliaries of vegetation, soon appeared to be estab- 

 lished. 



We must not blind ourselves to the fact, however, that the parti- 

 sans of gypsum were guilty of exaggeration. They spoke of the 

 substance as a universal manure, capable of supplying the place of 

 every other, as advantageous for every description of crop, as appli 

 cable to every variety of soil. Experience soon set bounds to sue! 

 indiscriminate laudation ; it was found that gypsum alone was inad- 

 equate to produce fertility, that it always required the concurrence 

 of organic manures, if the soil did not contain them of itself; that 

 it only acted beneficially on a certain, and that a very small number 

 of plants ; lastly, that it was upon artificial meadows, constituted by 

 clover, lucern, and sainfoin, that it produced its best effects ; its 

 action, on the contrary, being scarcely perceptible upon natural mead- 

 ows, doubtful in connection with hoed crops, and null with the cereals. 

 These negative results cannot be called in question ; they were come 

 to by parties who were every way interested in having the decision 

 otherwise. 



The best season for spreading gypsum is the spring, and when the 

 clover, sainfoin, or lucern, has already made a certain degree of 

 progress ; calm and moist weather is the best for laying it on. 

 Opinion wa* long divided as to whether it should be applied in its 

 natural state, and simply ground, or first burned and then ground. 

 But it is now generally admitted that burning adds nothing to the 

 qualities of gypsum. Although the usual practice is to sow or pow- 

 der the meadows with the ground gypsum, it is still acknowledged 

 that good elfects are obtained from incorporating the substance witii 

 the soil. The advantage of the practice of scattering it on in pow- 

 der, so as to adhere to the wet leaves of the growing plants, I find 

 explained in the equality of distribution which is by this means 

 effected. 



In some places, the number and extent of which are by no means 

 inconsiderable, no good effect whatever has attended the application 

 of gypsum, although it has been administered in favorable conditions, 



