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II. On the Use of Charcoal Dust, as a Top Dressing for 

 Onions, and as a Cure for the Clubbing in Cabbages, fyc. 

 In a Letter to the Secretary. By Mr. Thomas Smith, 

 Corresponding Member of the Horticultural Society, Gar- 

 dener to Matthew Bell, Esq. F. H. S. at Woolsington, 

 Northumberland. 



Read August 3, 1824. 



Sir, 



Having seen some Papers in the Transactions of the Horti- 

 cultural Society upon the cultivation of Onions, but none that 

 took any notice of a disease to which those roots are very 

 subject, I venture to lay the following experiments, and then- 

 results before the Society. 



The garden I superintend is a very wet, stiff soil, upon a 

 strong clay, and without any declivity. For several years 

 my crops of Onions were nearly all destroyed by a grub, 

 and by mouldiness coming on about their roots at various 

 stages of their growth ; sometimes when they were about the 

 size of what we call Scallions, at other times when they were 

 beginning to form a bulb, and even when the bulb was 

 formed. 



As soon as the disease takes place, it may very readily be 

 perceived by the Onion blade assuming a glaucous green 

 colour, but very soon after changing to yellow, and the leaves 

 at the same time rather flag. I tried various quarters in the 

 garden, and found that there was a difference in them, some of 

 them producing more of the disease than others. I also tried 



