mixed with the Food of Animals. 21 



animal substances undergo the changes necessary to qualify 

 them to become the food of plants. This, however, I can- 

 not, from any appearance in the soil when the plants were 

 taken up, assert to have been the case. 



The extraordinary effects of salt, when combined with 

 soot, are strikingly singular. There is no reason to sup- 

 pose these effects were produced by any known chemical 

 agency of soot or salt on each other. Were I to euess at 

 the producing cause, T should conjecture it to be that pro- 

 perty of saline substances by which they attract moisture 

 from the atnlosphere ; for I observed those beds where salt 

 had been used were visibly and palpably moisten than the 

 rest, even for weeks after the salt had been applied ; and 

 this appearance continued till rain fell, when of course the 

 distinction ceased. This property of attracting moisture 

 had greater influence possibly on the soot than on any of 

 the other manures, as soot, 'from its acrid and dry nature, 

 may be supposed to require a greater proportion of water to 

 dilute it than those substances which contain water already, 

 it may be proper to observe, that on those beds where salt 

 had been used the plants were obviously of a paler green 



u"u"t ^u^ '"^'*' ^^''"=^ "°^ •^^^ luxuriant ; a circumstance 

 which I thought worth noticing, and which I considered, 

 though erroneously (as appeared by the event), to indicate 

 a want of vigour, which would be felt in the crop. It was 

 observable also, that where salt was applied, \\hethcr by 

 Itself, or. in combination, the roots were free from that 

 scabbiness which oftentimes infects potatoes, and from 

 which none ot the other beds (and there were in the field 

 nearly forty more than what made part of these experi- 

 ments) were allogether exempt. 



Two sets of experiments, and with the same proportions 

 ot manures, were tried with turnips and buck-wheat, on a 

 soil the poorest I could meet with, which produced only a 

 dwarf heath and lichen, and winch I had had paicd off. 

 llic povcrtv ot tins soil will appear by the foilowino- ana- 

 lysis ; ' ° 



.„,. _ • <• -,- Grains. 



400 grains pave of siliceous sand - - 390 



Of finely divided matter, which ;ippeaicd as brown 



mould - . _ - 68 



Loss in water - _ _ - 12 



400 



I he finely divided matter lost by incineration nearly half 

 B 3 it5 



