266 TIIE FARMER AT HOME. 



render them pulverulent, the marl not only impi Dves the growth of 

 grass from its action as a mulch, but by slow solution, loth its alumin- 

 ous and calcareous portions are carried into the soil, rendering the soil 

 more retentive of manures and less liable to suffer from the effects of 

 drought. Sand marl is also useful for clay soils, and to any soil defi- 

 cient of lime. Slate or magnesian marls are seldom of much value, 

 and should only be used in localities where better marls or lime can- 

 not be procured. Shell marls are of various qualities, some of them 

 containing both sulphate and phosphate of lime, and therefore are of 

 great value. This kind of marl forms in part the subsoil of a small 

 portion of land near Jersey City, and on which cabbages have been 

 grown every year for half a century. 



Marl, like lime, strictly speaking, is not a manure. When added 

 to the soil, it acts as an ameliorator in improving its texture and mo- 

 difying its natural condition, rather than by giving materials for the 

 growth of vegetation. Its action upon the soil, and the benefits de- 

 rived from its application, are akin to those of lime, for it is, in fact, 

 but the carbonate of lime reduced to powder, and mixed with earthy 

 matters. It slakes and expands when exposed to the air, and in com- 

 mon with lime, possesses the property of rendering stiff' soils friable 

 and easier of cultivation, and of giving more compactness to those too 

 sandy and light. It also promotes the decomposition of vegetable 

 matter, neutralizes acids, and induces the formation of the nitrates 

 requisite to the highest fertility. It gives activity to the inert vege- 

 table matters often present in barren soils, as its successful employment 

 in the renovation of over-cropped and worn-out lands in many districts 

 in this country, particularly along the seaboard and in the South- 

 western States, most abundantly prove. 



MASTICATION. This is the action of chewing, or of agitating 

 the solid parts of our food between the teeth, by means of the motion 

 of the jaws, the tongue, and the lips, whereby it is broken into small 

 pieces, impregnated with saliva, and so fitted for deglutition and a more 

 easy digestion. 



MASTIFF. This species of dog is peculiar to England. It is 

 nearly of the size of a Newfoundland dog, strong and active, possessing 

 great sagacity, and is commonly employed as a watch dog. The 

 mastiff is said seldom to use violence against intruders, unless resisted, 

 and even then he will sometimes only throw down the person, and 

 hold him for hours, without doing him further injury, till he is relieved. 

 He has a large head, with short pendent ears, and thick lips hanging 

 down on each side. In the reign of James I., a contest was exhibited 

 between three mastiffs and a lion, in which the king of beasts was 

 compelled to seek for safety in flight. 



MASTODON, OR MAMMOTH. .This animal, which must have 

 been many times larger than the elephant, is now extinct, and all 

 that remains to attest its former existence a -e the bones, which are 



