92 THE BOOK OF THE ROSE chap. 



which are gritty, it would be interesting to know if 

 their ashes would show a larger proportion of silica, 

 or whether it is only the extra drainage and conse- 

 quent heat of the soil that proves favourable to them. 



Iron is present in but small quantities, highest in 

 the stem and lowest in the flowers. Sulphate of 

 iron is said to give a better colour to the foliage, 

 and in some sorts, such as Anna Olivier, to the 

 bloom as well, but I do not place much reliance on 

 it. In fact I have sometimes omitted the iron from 

 the formula below, for the small quantities cause a 

 good deal of trouble to the makers, but it should be 

 remembered that every one of the constituents is 

 necessary, or the others are by so much rendered 

 valueless ; so perhaps it had better be included, 

 though most soils and natural manures have it in 

 sufficient quantity. 



The following is the mixture recommended by Mr. 

 Tonks for the Eose, as deduced from the ash analysis : 



Superphosphate of lime, 12 parts. 

 Nitrate of potash, 10 parts. 



Sulphate of magnesia, 2 parts. 

 Sulphate of iron, 1 part. 



Sulphate of lime, 8 parts. 



33 parts. 



The manure is to be applied in early spring : 

 immediately after pruning would generally be soon 

 enough perhaps, but February would be better. It 

 is to be evenly scattered on the previously hoed 

 surface, at the rate of I lb. to the square yard, so 

 that the Eose grower can soon calculate how much 



