122 THEORY OF FEEDING. 



(p. 98) ; and also has a constipating effect, as we may see 

 when an animal is fed almost exclusively on straw. 



3. An excess of starch and fat tends to produce an obese 

 condition in horses which are not sufficiently worked. When 

 the labour is severe, there is no danger of a horse eating too 

 much food of this kind. Obesity in idle horses is apt to set 

 up fatty infiltration of the tissues and conseqent weakening of 

 the system, and possibly fatty degeneration. Linseed is the 

 only ordinary horse food which contains a proportion of 

 fat high enough to render it a laxative, if given in large 

 quantities. 



4. The bad results of an excess of nitrogenous matter, 

 although less hurtful to a busy horse than to an idle one, 

 cannot be entirely counteracted by work, however severe 

 or prolonged the labour may be. Its so-called " heat- 

 ing " effects appear to be chiefly due to (i) the presence 

 in the system of an abnormally large quantity of waste 

 nitrogenous products which produce a poisonous action on 

 the body ; and (2) the presence of an excess of sulphuric 

 acid, which is formed, as Bunge tells us, from the sulphur 

 contained in the nitrogenous debris and which is capable of 

 acting in a destructive manner on the tissues. If the system 

 contains a good supply of soda, potash, and lime, the sulphuric 

 acid will become neutralised on uniting with these bases, 

 which are found far more plentifully in hay, clover, lucerne, 

 and bran, than in corn. Common salt is not capable of 

 neutralising sulphuric acid, and consequently an addition of 

 it to the food will not prevent corn from having a " heating " 

 influence. 



In the equine disease which is known to stablemen as 

 " weed " or " Monday morning disease " (lymphangitis), we 

 have an admirable instance of the hurtful effects of too much 

 nitrogenous food, combined with too little exercise ; for the 

 malady in question is practically confined to highly fed horses 



