THE FARMER AT HOME. 



38? 



the kind of coal used for fuel, and with the circumstances under which 

 it is burned. From whatever variety it is derived, it will contain a 

 number of organic as well as inorganic bodies, including a considera- 

 ble portion of coal ashes, which have been carried up and lodged in 

 the chimney by the draught. One of its most prominent ingredients 

 is the large amount of ammonia it contains. Besides this, it yields 

 the phosphates, the sulphates, carbonates, and chlorides of lime, 

 potash, soda, iron, and magnesia, which are the principal inorganic 

 ingredients, and show that soot is quite a powerful manure. A few 

 years ago it was stated in an English paper, that soot had been suc- 

 cessfully used for potatoes, uroducing a great yield and preventing the 

 rot. 



SOLIDITY. In Physics, a property of matter or body, whereby 

 it excludes every other body from that place which itself possesses. 

 Solidity in this sense, is a property common to all bodies, whether 

 solid or fluid. It is usually called impenetrability ; but solidity 

 expresses it best, as carrying somewhat more of positive with it than 

 the other, which is a negative idea. The idea of solidity, Mr. Locke 

 observes, arises from the resistance we find one body make to the 

 entrance of another into its own place. Solidity, he adds, seems the 

 most extensive property of body, as being that whereby we conceive 

 it to fill space ; it is distinguished from mere space, by this latter not 

 being capable of resistance or motion. It is distinguished from hard- 

 ness, which is only a firm cohesion of the solid parts, so as they may 

 not easily change their situation. The difficulty of changing situation 

 gives no more solidity to the hardest body than to the softest ; nor is a 

 diamond properly a jot more solid that water. By this we distinguish 

 the idea of the extension of the body, from that of the extension of 

 space ; that of body is the continuity or cohesion of solid, separable, 

 movable parts ; that of space the continuity of unsolid, inseparable, 

 immovable parts. 



SONG OF BIRDS. The song of birds has been defined to be a 

 succession of three or four different notes, which are continued without 

 interruption through the same intervals, in a bar of four crotchets, 

 adagis, or whilst a pendulum sv/ings four seconds. It is observed, that 

 notes in birds are no more innate than language in man, and that they 

 depend entirely on the master under which they are bred, as far as 

 their organs will enable them to imitate the sounds which they have 

 frequent opportunities of hearing ; and their adhering so steadily, even 

 in a wild state, to the same song, is entirely owing to the nestling 

 attending only to the instruction of the parent-bird, whilst they disre- 

 gard the notes of all others that may, perhaps, be singing round them. 



Birds in a wild state do not commonly sing more than six or seven 

 months out of the twehre ; but birds that are caged and have plenty 

 of food sing the greater part of the year ; and we may add, that the 

 female of no species of bird sings. It has been remarked, that there 



