FkrtilizeIrS and Feeding Stuffs. 375 



for another type. Therefore, for several reasons, it is often preferable 

 for the farmer to prepare his own mixtures. This can readily be done 

 on a clean floor, taking care that the ingredients employed are in a 

 fine state of sub-division and are thoroughly and uniformly mixed. 

 Caution is to l)e shown in the choice of ingredients, for there are some 

 substances which cause a deleterious chemical or physical reaction 

 when intimately mixed, especially if the mixture is jdlowed to remain 

 for some time before being sown, so that the resulting product 

 deteriorates in value very considerably. For example, the mixing of 

 a material containing lime, especially if caustic, with superphosphate 

 would cause a partial reversion of the water-soluble phosphate to a 

 less soluble and available form. It must, however, be admitted that 

 many firms put their mixed fertilizers on the market at a reasonable 

 cost and in a better mechanical condition than a farmer can hope to 

 prepare his home-made mixtures. It therefore behoves every buyer 

 to scrutinize each price list very carefully and calculate which is 

 more economical, to purchase a particular brand o<f mixed fertilizer 

 at a fair value, or to compound his own special mixture. 



It must again be emphasized that the above unit values are not 

 given for the purpose df indicating the agricultural value of a fertilizer 

 or the return which may reasonablv be expected from the use of it, 

 for that is also largely controlled by (among other factors) the season, 

 character of the soil, kind of crop, and method of applying the 

 fertilizer. 



Oilier Considerations concerning the Valve of a Manure. 



Another point to remember is that no attempt has been made 

 when making the lists of unit values to differentiate between the 

 quality of the ingredients of the same nature in different fertilizers. 

 The mechanical condition of the ingredients in a fertilizer is an 

 important consideration, and especially is this true of those fertilizing 

 constituents which are insoluble. It may be laid down as a general 

 principle that the availability of a given insoluble fertilizing con- 

 stituent will vary with its fineness, and for this reason, in case of such 

 fertilizers as bone meal and basic slag", the fineness of the material 

 must be guaranteed to be within certain limits. As before mentioned, 

 in the above list the insoluble phosphate in the coarsest bone meal is 

 assumed to be o^f the same value as that in the finest bone flour, which 

 in practice is far from being the case. Another thing in connection 

 with' the mechanical condition of fertilizers is to insist that all the 

 ingredients present have an approximately equal degree of fineness, 

 for if a heavy, finely-ground material (for example) is mixed with 

 coarse, bulky material they will soon become more or less separated, 

 and the result will be a fertilizer very variable in composition and 

 from which it would be very difficult to obtain a representative sample 

 for analysis, the coarser material preponderating at the top of the bag 

 while the finer material will have worked its way down to the bottom. 



Analysis of Fertilizers to Farmers. 



The sale of fertilizers and farm foods throughout the Union is 

 now regulated under the Act No. 21 of 1917, according to which 

 " Every person who sells any fertilizer (or farm food) sliall g'ive or 

 send to the purchaser at the time of delivery an invoice stating the 

 quantity sold, the name or brand under which the fertilizer (or farm 



