PREPARATION OF FOOD. 217 



always like it. Its effects, when constantly used, &re of such 

 a doubtful nature, that I think every horse should have it in 

 his power to take or to refuse it as he is disposed. That he 

 may do so, he should be supplied with 



Rock Salt. — The salt which is sold under this name in 

 Glasgow, is brought from Cheshire, and is employed chiefly 

 for cattle. It is procured in large masses, of a stony hard- 

 ness. It is somewhat different from common salt, of which, 

 however, it contains 983 parts in 1,000 ; the rest is sulphate 

 of lime, muriate of lime, muriate of magnesia, and some in- 

 soluble matter. It is not likely that these make it different 

 to the horse from common salt. It is better, only, I believe, 

 because it can be obtained in a solid form. Most of the 

 coach proprietors in this neighborhood give it to theii horses 

 all the year round, and they give no other. It is not mixed 

 with the food. A lump, weighing perhaps two or three 

 pounds, is placed in the manger ; when all consumed, it is 

 replaced by another piece. With few exceptions the horses 

 seem to be very fond of it ; some always refuse it ; and 

 many reject it at one time, who greedily devour it at another. 

 Those that have not been used to the salt, are apt to eat a 

 large quantity on the first day, and, in general, these are 

 slightly purged on the next. Afterward, instead of eating the 

 salt, the horse contents himself with licking it. The per- 

 manent result is not always apparent. In very many cases 

 I have never been able to trace either good or evil to its use. 

 In some there has been a remarkable change, the lean and 

 spiritless becoming plump and animated. 



Nitre, I have said, is frequently given in boiled food. 

 Many foolish stablemen keep it constantly by them as an ar- 

 ticle of indispensable utility. They say it cools the blood, 

 and takes away swellings of the legs. 



Nitre is a diuretic of considerable power, and like all 

 others, tends to reduce watery swellings, such as those to 

 which the legs of horses are subject when they stand much 

 in the house, when they are too highly fed, and when the 

 legs are not sufficiently hand-rubbed. It excites the kidneys 

 to secrete more urine : the urine is a certain portion of the 

 blood, and, to replace what is lost by the kidneys, that which 

 is superfluous about the legs or the sheath is taken up. To 

 speak of nitre cooling the blood is nonsense, very evident to 

 any body not very ignorant. [It promotes evacuation by the 

 kidneys and skin, and by reducing the system, it acts to cool. 



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