188 SCIENTIFIC FEEDING OF ANIMALS 



leguminous plants, such as the gorse and the Java 

 bean(Phaseolus lunatus), are poisonous, and the latter 

 has been the subject of numerous investigations. It 

 has been found that when the crushed seeds are 

 stirred in water, or come in contact with the digestive 

 juices, the very poisonous prussic acid is formed, 

 under the action of an enzyme. This acid can be 

 got in small quantities from some of the vetches ; 

 the ordinary fodder vetch also contains a little. The 

 climate and weather seem to have a great influence 

 upon the formation of those substances which yield 

 prussic acid. 



All the leguminous seeds, when insufficiently 

 ground or improperly prepared, tend to cause dis- 

 tension and constipation. When given in large 

 quantities they cause thickening of the blood, and 

 in this respect vetches are the worst, then come 

 peas, whilst field beans least of all. On this account 

 caution should be exercised in the use of leguminous 

 seeds, particularly with horses, and they should be 

 reserved principally for hard-working animals of 

 coarse breeds. For them ^-J, at most \> of the corn 

 may be given in this form, but much depends upon 

 the amount of work done. Draught oxen and 

 fattening stock of all species, particularly pigs, 

 are well suited for a diet of leguminous seeds, 

 the meat from the latter animals being then excel- 

 lent. Vetches are said to react unfavourably 

 upon the taste and quality of the milk, but recent 



