26 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



siderably, and indeed need not wait for it, as so many men have 

 to do, till they lose their tempers and prejudice their crops. 



When special manures are found to be good, they contain 

 the above-named ingredients, and possibly others, which may act 

 beneficially in certain soils ; thus magnesia for Potatoes and Peas ; 

 soda for Asparagus and Carrots, and chlorine for Beet and Onions 

 (both imparted by common salt), and a little iron for most crops. 

 According to the experiments of Dr. Griffiths, principal of the 

 Lincoln School of Science, many soils do not contain sufficient 

 of this ingredient. His " Treatise on Manures," which is an 

 admirable work, contains striking examples of half a hundred- 

 weight of iron sulphate (green vitriol) per acre increasing the 

 crop of Potatoes, Turnips, Mangolds, Cereals, and Beans, while 

 it cured the stubborn root disease of Cucumbers (according to 

 the evidence of Mr. Crocker, of Ham Green Tomato fame), and 

 gave him extraordinary crops. Passing for a moment from 

 vegetables, Mr. Divers has recently stated in the Gardeners' 

 Chronicle its efficacy in curing a fine Peach tree of " yellows." 

 I have seen the tree, and can pronounce the cure complete. For 

 vegetable crops about a quarter of an ounce to the square yard 

 will suffice for experimental purposes, either in solution or 

 powder, this to be applied only when the soil is wet to yellowish- 

 looking plants and crops, for producing colouring matter or 

 chlorophyll. It should be remembered that lime is essential for 

 all garden crops, and that salt is good for all, and should be 

 applied in inland districts, especially to naturally clay soil, at 

 the rate of 2 cwt. per acre, or nearly an ounce to the square 

 yard, in spring. 



But while the soil must be fed for feeding the crops, it is 

 possible to impair its productiveness by over-manuring, espe- 

 cially with matter from stables of milking cows, and decayed 

 leaves. I once took possession of a garden that was like a mass 

 of humus, through additions of that nature for generations 

 perhaps. A walking-stick could be pushed down it to the handle 

 easily. One plot, I was told, would grow Potato-plants, but no 

 tubers. I found that to be a fact, and recorded it in the Journal of 

 Horticulture at the time. Peas were yellow and profitless. The 

 soil was poisoned with acids, and lime was needed to neutralise 

 them, also to set free the dormant nitrogen. It was given 

 freely (a bushel to the square rod— 30^ yards). Potash and bone 



