358 VETEEINAEY HYGIENE 



In the mixed excreta of all animals but the pig, the 

 feces are in larger amounts than urine ; in the pig, as in 

 man, there is more urine than fsEces, though this again 

 depends upon the nature of the diet. In making this com- 

 parison it is to be understood the excreta is weighed in its 

 natural state and not dried. 



Only a small proportion of the solid excreta finds its way 

 down drains; on the other hand, the bulk of the fluid 

 material escapes by this channel. The daily amount of 

 urine may, on an average, be taken at : — 



14 lbs. per diem for horses 

 26 „ „ cattle 



10 „ „ pigs 



1 „ „ sheep 



These amounts are liable to great variation, depending 

 on diet, season, etc., so that the above can only be regarded 

 as mean quantities obtained by different observers. 



Dyer* states that a fair average annual production of 

 manure per ton of live weight is 25 tons of a mixture of 

 excreta and litter combined, and this after remaining in a 

 manure pit for an average duration of time weighs 19 tons. 



The urine of the herbivora readily undergoes chemical 

 change, the urea breaking up into ammonium carbonate, 

 which gives a distinctive odour to badly- ventilated and ill- 

 drained stables.f 



The faeces of the herbivora present great differences in 

 their physical condition due to the amount of water they 

 contain ; in the horse they are moulded into balls and 

 comparatively firm ; in the ox they are pultaceous ; in the 

 sheep firm and dry ; in the pig human like and offensive. 



* Dr. B. Dyer, ' Conservation of Farm Yard Manure,' Journal 

 Boyal Agricultural Society, vol. iv., part iv. 



t During the Napoleonic wars the supply of nitre for gunpowder was 

 out off by the British fleet, but the old stables of Paris afforded an 

 unfailing source. The mortar was found to consist of nitrate of lime, 

 which was formed by the nitrifying organisms from the ammonia of 

 the stable air. The nitrate of lime formed an abundant crystalline 

 crop, from which nitre was readily obtained. — Dr. Aitken, Transactions 

 of the Higliland and Agricultural Society, 5th Series, vol. xi. 



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