TlIK IjULLKTIN. 11 



2. Ash is the inorg-anic or iiiiiicral matter of plaiils, ainl is tiie 

 residue left after burning- till all volatile material is driveu off. It 

 is composed mainly of soda, potash, lime and magnesia, in the form 

 of phosphates, sulphates, chlorides and carbonates. Ash furnishes 

 the materials for the bony siructurc of animals, and enters to a much 

 less extent into the tissues and organs. 



3. Fats (Ether Extract) represents whatever is dissolved from 

 foods by dry ether. It is composed mainly of fats and oils, l)ut con- 

 tains, in addition, quantities of gums, wax and coloring nuitter, de- 

 pending upon the substances extracted. 



4. Protein, the term as used in connection with fodder analyses, 

 includes Albuminoids and Amides, the albuminoids being the more 

 valuable and at the same time composing by far the larger portion 

 of the protein compounds. They are the nitrogenous compounds of 

 plants and animals and are determined by estimating the nitrogen 

 in them, which element composes about 16 per cent of the weight 

 of protein substances. JSTone of the other classes of substances con- 

 tain nitrogen. They are represented^ in the animal body by liga- 

 ments, lean meat, muscles, tendons and tissues. 



5. Crude Fiber or Cellulose is the cell wall and structure material 

 of plants, and is usually the most indigestible portion of them, but 

 when digested is considered of equal value to starch and sugar. The 

 lint of cotton is almost pure cellulose. Its composition is similar to 

 that of starch. It is determined by boiling the food stuff with weak 

 acid and alkali, thus dissolving all other constituents. Crude fiber 

 and nitrogen-free extract taken together are known as carbohydrates. 



6. Nitrogen-free Extract is the term applied to those non-nitrog- 

 enous constituents of foods which are represented in the main by 

 sugars, starch, dextrin and gums. They all contain carbon, hydrogen 

 and oxygen, but no nitrogen, as does protein, i^itrogen-free extract is 

 estimated by difference, it being equal to the difference between the 

 sum of the above five constituents — water, ash, protein, fats and 

 crude fiber — and 100. It is, perhaps, the most inaccurate of all the 

 determinations in a food analysis, inasmuch as all. the errors and 

 differences in the other determinations fall upon it. 



Dry Matter and Organic Matter. — Neither of these terms repre- 

 sent a single class of constituents or nutrients. Dry matter is wdiat 

 is left of a plant or food stuff after the water is driven off or sub- 

 tracted, and organic matter is dry matter minus the ash. For exam- 

 ple : if the original food stuff as fed is represented as 100 per cent and 

 it contains 10 per cent of water and 5 per cent of ash, then dry mat- 

 ter is equal to 100 per cent, less 10 per cent water, or 90 per cent, 

 and organic matter is 90 per cent dry matter, less 5 per cent ash, or 

 85 per cent. 



To enable those not familiar with the subject to gain a clear idea 

 of the parts of food stuffs, and the terms representing them as used 

 in fodder analyses, the following statement is presented : 



