The Nerjlcct of Chemistry hij Practical Farmers. 427 



and the reason of their having received different names is on 

 account of their different appearance and action towards re-agents. 

 And these facts have led Liebig to believe that we may estimate 

 the flesh-producing power of any crop by the quantity of azotised 

 proximate elements contained in it. My object in giving these 

 proximate organic analyses is to test the truth of this theory by 

 the practical experience of farmers ; of course, in investigating 

 this question allowance must be made for the various feeding 

 habits of different species of animals, as also for the different 

 degrees of digestibility of the food. 



But here let me caution my readers against placing too much 

 dependence on these proximate analyses when the result of a 

 single analysis only, for it must be allowed that chemists up to 

 this time have not acquired such proficiency in this department of 

 their science as they have in the ultimate organic and inorganic 

 analyses, which latter fact has caused the majority of chemists to 

 estimate the amount of azotised proximate elements from the 

 previously ascertained quantity of nitrogen contained in the crop 

 in question. This they are easily able to do, for as each of the 

 azotised proximate elements contains about 15*75 per cent, of 

 nitrogen, if we multiply the amount of nitrogen contained in the 



crop in question by piry^ 6*35, it will, of course, give us the 



total amount of azotised proximate elements ; though for all 

 practical purposes I think that we might omit the decimals, and 

 merely multiply the nitrogen by 6. In all doubtful cases I would 

 certainly recommend this method of calculating their amount to be 

 adopted. 



Fat, Oil, Starchy Gum, Sugar, Fibre. — These are the unazo- 

 tised proximate elements of vegetables, containing no nitrogen. 

 The four latter are combinations of carbon, with oxygen and hydro- 

 gen, in the proportion in which they form water, and as they are 

 capable of being transformed from one to another, their different 

 forms are not always distinctly defined. The fatty oils differ from 

 the preceding, in being principally composed of carbon and hydro- 

 gen, with a much smaller proportion of oxygen. Liebig supposes 

 that these unazotised proximate elements are the fat and heat pro- 

 ducing portion of the crop. I leave it to the intelligent farmer to 

 decide whether the theory is tenable, merely premising that the 

 fibre must be kept out of their calculations on account of its 

 indigestibility. 



Inorganic Portion, or Ash. — We now come to consider the 

 inorganic portion, or ash — in other words, the part that is not 

 dissipated by the action of fire. This when analysed is found 

 to consist of about 13 elements, more or less, including alumina, 

 manganese, and carbonic acid ; the presence of the first of these in 



