406 MAINTENANCE OF ANIMALS. 



First weighing : Both horses 2010 lbs. Average of each 10045 



Second " " 1927 " 963.0 



Loss in 11 days 83 41.5 



In fact, with such a ration as this, in which water was made to 

 replace solid corn, no other result could reasonably be expected. 

 In continuing it, the health of the horses would very certainly have 

 soon been seriously compromised. There is no objection to rye in 

 Itself as an element in the food of a horse ; but then it must be sub- 

 stituted in the quantity indicated by the table of equivalents, by 

 adopting which, Mr. Dailly found that he could keep the post-horses 

 of Paris in good heart, at a time when the difference between the 

 price of oats and rye made it advantageous to substitute the latter 

 for the for.rier. The experiments of Mr. Dailly on the subject were 

 so decisive and so ably conducted, that I felt myself relieved from 

 the necessity of inquiring further into it myself. 



From these experiments, the particulars of which have now been 

 given, it may be conc'uded that the nutritive equivalents of the po- 

 tato, beet, Jerusalem potato, and carrot, as they come out upon ana- 

 lysis, or as they are inferred from the amount of azote they contain, 

 may be adopted without detriment to the health of horses. If they 

 err at all, it is that they assign equivalents somewhat too high, 

 which is the same ay saying that their actual nutritive power is 

 rather less than these numbers give it ; so that a portion of the hay 

 of the standard ration being substituted for its equivalent of tuber or 

 root, the diet will be improved. 



Thus, 100 of good meadow-hay may be taken, as ascertained by 

 experiment, to be equivalent to : 



280 potatcjs — ^by analysis, equal to 315 



280 Jenisaiems 311 



400 beet 548 



400 Swede (too little) 676 



400 carrot 382 



In the following table of nutritive equivalents, to the numbers as- 

 signed by the theory, I have added those of the whole which I find 

 in the entire Heries of observations that have come to my knowledge. 

 I have also given the standard quantity of water, and the quantity of 

 azote, contained in each species of food. When the theoretical 

 equivalents do not differ too widely from those supplied by direct 

 observation, I believe that they ought to be preferred. The details 

 of my experiments, and the precautions needful in entering on and 

 carrying them through, must have satisfied every one of the difficul- 

 ties attending their conduct ; yet all allow how little these have been 

 attentively contemplated, and what slender measures of precaution 

 against error have been taken. Our equivalent for field-beet is 400, 

 a number come to by introducing 44 lbs. of the root into the ration, 

 in lieu of 11 lbs. of hay ; had we introduced 56 lbs., the equivalent 

 number would have come out 500 ; and it is questionable whether 

 the final result would have been aflfected by this substitution. In 

 my o'pinion, direct observation or experiment is indispensable, but 

 mainly, solely as a means of checking within rather wide limits tljp 

 w?'}!^? of cheiflicjl analysi?, 



