21 S OPEN AIR GEAPE CULTURE. 



turbid, it carries with it in suspension a large quan- 

 tity of fine sedimentary matter, which fills up the 

 interstices of the soil, or, deposited upon the roots 

 themselves, greatly impedes their power of absorp- 

 tion. If applied when plants are torpid, it either 

 acts as in the case of being over strong, or it actually 

 corrodes the tissues. 



" Let the manure be extremely weak ; it owes its 

 value to matter that may be applied -with consider- 

 able latitude ; for they are not absolute poisons, like 

 arsenic and corrosive sublimate, but only become 

 dangerous when in a state of concentration. Gas 

 water illustrates this ; pour it over the plant in the 

 caustic state in which it comes from the gas-works, 

 and it takes off every leaf, if nothing worse ensues. 

 Mix it with half water — still it burns; double the 

 quantity once more — it may still burn, or discolor 

 foliage somewhat. But add a tumbler of gas water 

 to a bucketful of pure water, no injury whatever 

 ensues ; add two tumblers full, and still the effect is 

 salubrious, not injurious. Hence it appears to be 

 immaterial whether the proportion is the hundredth 

 or two hundredth of the fertilizing material. 



" Manuring is, in fact, a rude operation in which 

 considerable latitude is allowable. The dano^er of 

 error lies on the side of strength, not of weak- 

 ness. 



