108 THE farmers' handbook. 



A Few Simple Hints for Detecting Adulteration in 

 Artificial Manures. 



It must be premised that it is of no use attempting the roughest analysis 

 of a manure without a fairly accurate balance. The substances likely to be 

 added as adulterants, or whose presence in quantity lowers the value of the 

 manure, are not foreign matters, but those like sand, which already exist in 

 most manures ; therefore, all attempts to decide the value of a fertiliser must 

 depend upon an estimation of the quantities of the ingredients present, and 

 these cannot be estimated without a balance which must be capable of 

 weighing at least half a grain. 



In the absence of a balance, however, the following rough tests may be 

 found useful in giving an approximate idea of the purity of a few of the 

 simple fertilisers : — 



Bonedust. — A good sample of bonedust, however fine, shows the bony 

 structure in some of the larger pieces. It should be as dry as possible, and 

 in a fairly fine state of division. It should have the characteristic smell, 

 though there is no need that the smell should be offensive. It does not 

 follow that bone-meal is necessarily good because the odour is disgusting. 



Take about 100 grains in a small iron spoon or ladle ; heat it strongly in 

 a brisk fire. The heat should be applied cautiously at first to avoid loss by 

 spurting, after which it may be applied as strongly as possible. Any moisture 

 present, all the organic matter and carbonic acid are driven off by this 

 means, and the "ash" left behind contains phosphate and oxide of lime, and 

 magnesia, with a small quantity of alkalies. The ash should be quite white 

 if the bone-dust is pure, although it may require some patience and a pretty 

 hot fire to get it white. This ash is now allowed to cool, and emptied into a 

 glass beaker or a basin which will stand heat. If such a vessel is not at hand, 

 a small enamelled saucepan may be pressed into the service. Pour on to the 

 ash in this vessel about half a pint of water and a few ounces of hydrochloric 

 acid, and boil well for about five minutes. The substance should dissolve 

 completely in the acid, or leave only a very small residue. If there is any 

 considerable residue left undissolved, the presumption is that sand has been 

 mixed either purposely or accidentally. Allow this acid liquid to cool ; pour 

 it off from the sand into a tumbler or glass jar. A rough indication of the 

 quantity of phosphate of lime present may be gained as follows : — Add dilute 

 solution of ammonia until the liquid smells of ammonia. This will form a 

 dense white precipitate of phosphate of lime, and a little practice will enable 

 you to judge from the bulk of the precipitate after it has stood for two hours 

 of the relative proportion of this ingredient in the manure. If the same 

 quantity (100 grains) be taken in each case, you will know what quantity to 

 expect from a good sample. If no precipitate, or only a slight one is formed, 

 the manure may be discarded. I know of no method by which even an 

 approximation of the nitrogen can be made without apparatus. As sand is 

 the most likely adulterant, it will generally be sufficient to test for it as 

 above. This method will detect sand in bonedust, dried blood, offal, and 

 such products. 



Sulphate of ammonia should be a whitish crystalline powder, fairly dry 

 and friable. It should dissolve completely in water without leaving and 

 residue, and on placing some in the iron spoon used in the test for bone-dust, 

 and heating it strongly in the fire, it should completely volatilise, leaving no 

 residue. A fair idea of its purity may be inferred from the quantity of the 



