02 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



acid per acre from the soil as against 98 lbs. of nitrogen and 

 80 lbs. of potash ; a clover crop is practically independent of 

 nitrogen manuring, despite the 102 lbs. it contains per acre. 

 Ordinary arable soil, and still more so garden soil, contains at 

 least one hundred times as much plant food as the plant can 

 remove, though only part is in a condition immediately available ; 

 there is generally one particular constituent the plant finds a 

 difficulty in obtaining, and which must be supplied in excess as 

 manure. Given this excess in one direction, the plant can feed 

 itself in other respects, but the particular constituent each crop 

 needs can only be decided by actual experiment, which in the 

 case of garden crops has rarely been carried out. 



But the special point which the speaker wished to bring 

 before the attention of gardeners was the advisability of using 

 pure unmixed artificial manures, instead of the compounded 

 articles to which they generally trusted. There were three dis- 

 advantages in using these ready mixed manures ; they did not know 

 what they were using, and so had no means of reasoning back 

 from the results they obtained, and thus accumulating experience 

 for future use ; they paid absurd prices for even the good mixtures ; 

 and they had no protection from absolute fraud. 



Many of the fertilisers commonly employed by gardeners had 

 been sent to the speaker for analysis, and latterly he had made 

 a point of collecting and examining all he saw advertised in the 

 gardening papers ; as a general rule they contained organic 

 nitrogen and sulphate of ammonia, sometimes also nitrogen in 

 nitrate of soda, horn dust, Sec. The phosphatic part of the manure 

 W&e generally bone meal, often dissolved bone or superphosphate 

 was also added ; potash was present as kainit, but often omitted; 

 while fish-meal or ground cake residues were sometimes employed 

 as a general organic basis for the manure. 



The following table gives the result of these analyses. The 

 samples examined were either portions of large consignments or 

 were the contents of the shilling tins that are commonly sold, 

 and as it is practically impossible for the maker to deliver each 

 small parcel of uniform composition, the names of the makers 

 are not published. 



The valuation attached to each manure is arrived at by a 

 method which should be understood by every gardener, as it is 

 only by this means that the price demanded for any manure 



