76 



MANAGEMENT OF MANURE. 



In the second place, if the sole injury to 

 plants, of severe freezing, were that of ex- 

 tricating the air, which indeed always takes 

 place in the act of freezing, all plants ex- 

 posed to a greater degree of frost than their 

 structure naturally enables them to bear, 

 would as inevitably die as the freezing took 

 place. But this, it is well known, is not 

 the fact. On the contrary, a given plant, 

 that will not bear, under ordinary circum- 

 stances, to be exposed to a temperature 

 even a few degrees below the freezing 

 point, may be subjected to a temperature 

 within a few degrees of zero, provided it is 

 frozen gradually, and kept in the dark, and 

 very gradually thawed. Does not this go 

 to prove that it is rather to the mechanical 

 disturbance, distention, fracture, etc., caus- 

 ed in the sap vessels by sudden freezing 

 and thawing, than by any chemical change 

 brought about by the expulsion of the air 

 from the juices of the plant in freezing, 

 that we must attribute fatal effects — since 

 this separation of air must necessarily occur 



whenever freezing takes place, whether ice 

 crystals are formed slowly or rapidly ? 



That half-hardy plants, however, that ap- 

 pear partially injured at first, do often die 

 from the chemical change effected in their 

 juices by frost, can scarcely be denied. 

 But this does not appear to us to be the 

 only way, or indeed the usual one, by 

 which the death of trees is caused by frost. 



M. Morren's aphorism that the less wa- 

 tery, or,"" in other words, the more elaborated 

 is the sap of plants, the less liable are they 

 to be injured by freezing, is one that is not 

 only well established, but most interesting 

 practically to cultivators : since it teaches 

 them to prevent, in half-hardy trees, (either 

 by planting them on high and dry soil, or 

 otherwise checking over-luxuriance by root- 

 pruning,) all growth late in the season. 

 Early growth, well elaborated juices, and 

 thoroughly ripened wood, are the best safe- 

 guards yet known, against the injurious ef- 

 fects of freezing, on particularly tender 

 trees. — Ed.] 



<♦•»>■ 



HO"W TO MANAQE THE MANURE HEAP. 

 BY PROFESSOR LINDLEY, OF THE UNIVERSITY OF LONDON. 



No one, who has been watching the pro- 

 gress of agriculture for the last few years, 

 can for a moment dispute the importance of 

 the foreign substances, which, like nitrate of 

 soda and guano, have been introduced into 

 husbandry, But admitting to the fullest 

 extent, the value of these materials ; admit- 

 ing, too, the utility of some of the artificial 

 manures compounded for sale ; we must 

 observe, that it is most absurd for the culti- 

 vator to put himself to the expense of pur- 

 chasing them until he has utterly exhaust- 

 ed all the means which his farm affords 

 him, for nothing, of increasing the fertility 



of his land. Such substances should be 

 employed in aid of ordinary manure, not 

 instead of it. The art of farming and mar- 

 ket-gardening consists, or should consist, in 

 obtaining the greatest possible amount of 

 food at the smallest possible expense. 



Now, it must be obvious, that those ma- 

 nuring substances which are necessarily 

 produced on a farm, are the least expensive 

 of all things ; to the careful collection and 

 preparation of them should the good hus- 

 bandman turn his attention in the first in- 

 stance ; and when all the resources of skill 

 are exhausted upon that preparation, it is 



