DEFINITIONS AND TECHNICAL CONSIDERATIONS. 353 



there is a difference it must be attributed to the ration used. The percentage 

 of lime entering a ration has also an important influence upon the phosphoric 

 acid found in the urine, for the reason that phosphates are formed and are 

 either assimilated or rejected as the case may be. When feeding beets in some 

 special cases, calcic phosphate may be replaced by calcic carbonate. 



Digestibility of salt. In discussing fodders in general the importance of salt 

 was pointed out. and at present it is well to say that sodic chlorid is more of 

 a condiment than an actual food, as it stimulates the organs by indirect means 

 and thus increases the digestibility of other fodders. From the experiments of 

 Salzmiinde. it may be concluded that the action of salt is very variable; some- 

 times it appears to favor digestion, and then again it has a retarding action. 

 It is a mistake, from a fattening point of view, to confound the advantages to 

 be derived from forcing consumption of fodders by exciting the appetite, with 

 what occurs when the weight of an animal is augmented by a complete diges- 

 tion and consequent assimilation of the food furnished, as an animal may 

 consume more than it can assimilate and throw out the surplus in excrements. 



Digestibility of a*h. Potassa of fodders does not appear to be utilized during 

 digestion, as shown by the fact that 95 to 97 per cent, is found in the excre- 

 ments. The advantages of potassic phosphate do not come within the scope of 

 this present writing as they refer to swine feeding with special meat com- 

 pounds. Magnesia is partly utilized; just how, remains to be demonstrated. 

 As a general thing 20 to 30 per cent, of the total magnesia of a fodder is found 

 in the excrement, while of lime 95 per cent, is utilized, leaving but 5 per 

 cent, in excrement. Sulphuric acid and chlorin apparently take no part in 

 the assimilation of the body, and what applies to them may be said of all other 

 mineral elements, etc.. which the fodder contains. 



These facts should be sufficient to convince the farmers of the importance of 

 carefully collecting both liquid and solid excrements for use upon the soil as 

 fertilizers. It is too frequently maintained that beets, for example, exhaust 

 the soil, forgetting that by proper rotation of crops and fertilizer utilization, 

 the fertility may be indefinitely maintained. 



Digestion. Cattle in general. The main object of digestion is to bring 

 about an assimilation which is necessary to build up the wastes of the body. 

 The blood being the principal distributor, the liquids or solids to be utilized 

 must pass by osmosis through the membranes of the various organs in which 

 they are received. The principle of osmosis enables the crystalloids to 

 move through the tissue while the colloids or gum-like substances cannot 

 pa.^s. It is important to note that the passage in question depends upon the 

 nature of the substance. In some cases no transformation need be effected; in 

 others chemical combinations are necessary. These modifications, taken as a 

 whole, are what we call digestion. It is important not to confound laboratory 

 chemical changes with those of the many digestive processes. The entire 

 transformations of what might be called digestive chemistry, are very different 

 from what is admitted as being true chemistry as now taught in the text books, 

 and considerable confusion might arise if the two were not separately con- 



