soo 



so large and so distant as to greatly 

 increase the expense of carriage. 

 Not to enter into minute calculations, 

 it is fully proved that, to a certain ex- | 

 tent, soiling is protilablc and econom- 

 ical, when it can bo done before and 

 after the usual hours of labour ; but 

 that, when undertaken on a large 

 scale in anv one locality, it is usually 

 attended with loss, the manure pro- 

 duced being purchased at too great a 

 price." 



SOLANACE.E. A natural order 

 of herbaceous or shrubby exogens, 

 inhabiting all parts of- the world ex- 

 cepting the arctic regions. This or- 

 der contains nightshade, henbane, 

 mandrake, tobacco, stramonium, tiie 

 potato, and the tomato, the leaves of 

 all which are narcotic and exciting, but 

 in different degrees, from Atropa bel- 

 ladonna, which causes vertigo, convul- 

 sions, and vomiting ; tobacco, which 

 will frequently produce the first and 

 last of these symptoms ; henbane and 

 stramonium, down to some of the so- 

 lanum tribes, the leaves of which are 

 so inert as to be used as kitchen herbs. 

 Even in the potato plant, the narcotic 

 acrid principle is found in the stem 

 and leaves, and even in the rind of 

 the tuber. But tlie principal part of 

 the latter consists of starch ; and the 

 small quantity of deleterious matter 

 being volatile and near the surface, 

 is readily driven off by the heat used 

 in cooking. 



SOLIDUNGULATES. Ani- 

 mals with an undivided hoof, as the 

 horse. 



SOLUTION. The diffusion in wa- 

 ter or other menstrua of the particles 

 of a solid or other body. The amount 

 dissolved is definite at the same tem- 

 perature, and is usually increased by 

 heat. A fluid already holding in so- 

 lution a given substance will not dis- 

 solve so niuch of a third as if pure, 

 and sometimes none at all. 



SOOT. " Soot is a complicated and 

 variable mixture of substances pro- 

 duced during the combustion of coal. 

 Its composition, and consequently its 

 effects as a manure, vary with the 

 quality of the coal, with the way in 

 which the coal is burned, and with 



SOO 



the height of the chimney in which 

 it is collected. 



" Soot has not been analyzed since 

 the year 1826, when a variety exam- 

 ined by Braconnot was fi)und by him 

 to consist, in a thousand parts, of 



Ulniic acid? (a substance rcsemLlllll^r 



that portion of the vegetable matter 1,302.0 



of llie soil which is soluble in caustic 

 ])()tash) 



A leililish brown soluble substance, con- 1 

 taiuinif nitrofjen, and yielding ammo- > 200-0 

 nia when heated . . • • ' 



Asboline 



Carboiiateof lime, with a trace of mag- 

 nesia (proliably derived in part from 

 the sides of the chimney) . 



Acetate of lime 



Sulphate of lime (gypsum) . 



Acetate of niaanesi a .... 



Phosphate of lime, with a trace of iron 



Chloride of potassium . . . ■ 



Acetate of potash .... 



Acetate of ammonia . . . • 



Silica (sand) 



Charcoal powder 



Water 



50 



1466 



56-5 

 56-0 



5-3 

 15-0 



3-6 

 410 



20 



9-5 



38-5 



]95-0 



l(J00-0 



" The earthy substances which the 

 soot contains are chiefly derived from 

 the walls of the chimney, and from 

 the ash of the coal, part of which is 

 carried up the chimney by the draught. 

 These, therefore, must be variable, 

 being largest in quantity where the 

 draught is strongest, and where the 

 earthy matter or ash in the coal is the 

 greatest. The quantity of gypsum 

 present depends upon the sulphur 

 contained in the coal : that which is 

 freest from sulphur will give a soot 

 containing the least gypsum. The 

 ammonia and the soluble substance 

 containing nitrogen will vary with 

 the quantity of nitrogen contained in 

 the coal and with certain other caus- 

 es, so that the composition of differ- 

 ent samples of soot may be very un- 

 like, and their influence upon vegeta- 

 tion therefore very unequal. The 

 consequence of this must be, that the 

 results obtained in one spot, or upon 

 one crop, are not to be depended 

 upon as indicative of the precise effect 

 which another specimen of soot will 

 produce in another locality, and upon 

 another crop e%'en of the same kind ; 

 and thus it happens that the use of 

 soot is more general, and is attended 

 with more beneficial effects in some 

 districts than in others. 



737 



