CALCAREOUS QUALITY NOT KNOWN. 379 



delphia Agricultural Society,* [and in the late edition of Stephens 7 

 Book of the Farm, as quoted above]. It is. still more unlike mar/, 

 properly so called, than any of the substances described under that 

 name, in the foregoing quotations. This manure is-almost a pure 

 calcareous earth, being formed of the remains of small fresh-water 

 shells deposited on what were once the bottoms of lakes, but which 

 have since become covered with log or peat soil. If I may judge 

 from our beds of mussel shells (to which this manure seems to bear 

 most resemblance), much putrescent animal matter is combined 

 with, and serves to give additional value to these bodies of shells. 

 This kind of manure is sold in Scotland by the bushel, at such 

 prices as show that it is very highly prized. It seems to be found 

 but in few situations, and though called a kind of marl, is never 

 meant when that term alone is used by British writers. 



13. A much older work than either of these referred to fur- 

 nishes in part the definitions and even the words used above. This 

 is the " Systema Agriculturce. the Mystery of Husbandry dis- 

 covered," published in 1687 ; and the author or compiler of that 

 old work was probably indebted to others still older for his descrip- 

 tion of marl. For new books on agriculture, more especially, 

 have been most generally made by compiling and copying from 

 older ones. 



" Marie is a very excellent thing, commended of all that either write or* 

 practise any thing in husbandry. There are several kinds of it, some stony, 

 some soft, white, gray, russet, yelloiv, bleiv, black, and some red : It is of a 

 cold nature and saddens land exceedingly ; and very heavy it is, and will 

 go downward, though not so much as lime doth. The goodness or badness 

 thereof is not known so much by the colour, as by the purity and uncom- 

 poundness of it ; for if it will break into bits like a dye, or smooth like lead 

 oar, without any composition of sand or gravel ; or if it will slake like slate- 

 stones, and slake or shatter after a shower of rain, or being exposed to the 

 eun or air, and shortly after turn to dust when it's thoroughly dry again, 

 and not congeal like tough clay, question not the fruitfulness of it, notwith- 

 standing the difference of colours, which are no certain signs of the good- 

 ness of the marie. As for the slipperiness, viscousness, fattiness, or oyliness 

 thereof, although it be commonly esteemed a sign of good marie, yet the 

 best authors affirm the contrary viz. that there is very good marie which 

 is not so, but lieth in the mine pure, dry and short, yet nevertheless if you 

 water it, you will find it slippery. But the best and truest rule to know 

 the richness and profit of your marie, is to try a load or two on your lands, 

 in several places and in different proportions. 



" They usually lay the same on in small heaps, and disperse it over the 

 whole field, as they do their dung ; and this marie will keep the land 

 whereon it is laid, in some places ten or fifteen, and in some places thirty 

 years in heart: it is most profitable in dry, light, and barren lands, such as 

 is most kind and natural for rye, as is evident by Mr. Blithe's experiment 

 in his chapter of marie. It also aifordeth not its vertue or strength the first 

 year, so much as in the subsequent years. It yields a very great increase 



* Vol. iii. p. 206. 

 32* 



