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The anterior segment of the trunk of 

 insects, on which the head is placed. 



M.WXA. A sweet, gummy exu- 

 dation of the ash (F. onius) and oth- 

 er trees, used in medicine as a laxa- 

 tive. .Manna, dissolved in hot alco- 

 hol, and allowed to cool, deposites 

 a white powder {mannitc) ; this, al- 

 though sweet, is incapable of vinous 

 fermentation. 



MAXTEL. In building, the wood, 

 stone, &c., lying from one jamb to 

 the other of the chimney. 



MANTIS. A genus of orthopte- 

 rous insects, with an exposed head, 

 long and narrow body, and wings 

 plaited longitudinally : "they are vege- 

 table eaters. 



MANURES. Substances intended ' 

 to increase the fertility of the earth. 

 They are usually divided into miner- 

 al or fossil, animal, and vegetable ] 

 manures, as they are derived from 

 these kingdoms ; but in this way we 

 gain no knowledge of their action on 

 the soil or plants. A better division ' 

 is into Amendments, or such manures 

 as improve the texture of soils, as 

 lime, marl, peat ; Manures supplying 

 elements deficient in the soil, as gyp- : 

 sum, bone earth, ashes ; and, third- 

 ly, manures intended to advance or , 

 stimulate vegetation, as putrescent ; 

 animal matters. But the greater num- 

 ber of manures are natural composts [ 

 that supply everything necessary to ' 

 the development of plants, in a more I 

 or less concentrated form, as stable ' 

 manure, straw of different kinds, gua- 1 

 no, night-soil, &c. The manures are 

 treated under their separate heads. 



In the application of manures in- j 

 tended to remedy a defect in the soil, j 

 as gypsum where sulphuric acid is : 

 absent ; bone earth where phosphor- 1 

 ic acid is wanting, it may be econom- 

 ical, by an analysis of the soil, to be 

 certain that such a deficiency exists, 

 otherwise our manures might be bet- 

 ter applied elsewhere. But most of 

 our soils require good tillage, amend- 

 ments, and then natural composts to 

 increase the crop ; hence the values 

 of manures in the experience of the ' 

 farmer does not exactly coincide with 

 the theoretical value, and the amount 



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of nitrogen or stimulating element 

 they contain is in practice the best 

 criterion of their effects, the soil be- 

 ing in good order and tilth. Hence 

 Boussingault and Payen, practical 

 men, have constructed a table of the 

 value of all manures, as compared 

 with farm-yard manure, on this basis. 

 The first column gives the kind of 

 manure in its ordinary state, the sec- 

 ond the amount of water it contains, 

 the third and fourth the per centage 

 of nitrogen in the dry and wet states, 

 the filth and sixth the quality of the 

 manure in the dry and wet states, so 

 far as the effects of the ammonia or 

 nitrogen are concerned, the seventh 

 and eighth columns represent the 

 amount of the manures, respectively, 

 equivalent to 100 lbs. of farm-yard 

 manure, both in the dry and wet 

 states, so far as the nitrogen is con- 

 cerned. Thus we learn that 8 lbs. of 

 linseed oil-cake are equally servicea- 

 ble with 100 lbs. of farm-yard manure 

 in the ordinary state of moisture, &c. 

 (For table, see the following pages.) 



The greatest improvements in ma- 

 nures recently made are their econ- 

 omy for different plants, or the sys 

 tem of special manures referred to 

 under the principal crops in this work, 

 and their application with the seed 

 or on growing plants, by drills and 

 other contrivances. The old method 

 of scattering immense amounts over 

 the soil a long time before the crop 

 is justly considered unprofitable. 



The following table of the weight 

 of a cubic yard of several manures 

 is of some practical value : 



cwt5. qrs. lbs. 



Garden mould 19 3 25 



New dung 9 3 18 



Leaves and sea-weed ... 90 3 



Water 13 3 



Compost of dung, with weeds 



and lime 14 5 



— See Farm-yard Manure. 



MANURES, ARTIFICIAL AND 

 SPECIAL. These are compounds 

 prepared for sale to farmers, as arti- 

 ficial guano, poudrette, silicate of 

 soda, sulphate of soda, sulphate of 

 ammonia, soda ash, solution of bones, 

 saltpetre, and urate. Special manures 

 are those which are designed to ad- 

 vance particular crops. 



479 



