-------------------+------------+-------------------------+------------ | | | Phosphoric | | Water. | Nitrogen. | Acid. | Alkalies. +------+-----+------+-----+------+-----+------+----- | Per | Per | Per | Per | Per | Per | Per | Per | 1000 |cent.| 1000 |cent.| 1000 |cent.| 1000 |cent. |parts.| |parts.| |parts.| |parts.| -------------------+------+-----+------+-----+------+-----+------+----- Sheep (2 lb. hay }| 865 | 86.5| 14 | 1.4 | .5 | .050| 20 | 2.0 per diem) }| | | | | | | | | | | | | | | | Swine (winter food)| 975 | 97.5| 3 | .3 | 1.25 | .125| 2 | .2 | | | | | | | | Horses (hay and }| 890 | 89.0| 12 | 1.2 | - | - | 15 | 1.5 oats) }| | | | | | | | | | | | | | | | Cows (hay and }| 920 | 92.0| 8 | .8 | - | - | 14 | 1.4 potatoes) }| | | | | | | | -------------------+------+-----+------+-----+------+-----+------+----- Phosphoric acid is present in the urine of the farm animals in the most minute traces: practically, it may be considered to be wanting in the urine of the horse and the cow, and is present only in small quantities in sheep's urine. The pig's urine, indeed, contains it in larger quantities; but the percentage is still so small as to justify the statement that the urine of the common farm animals is not a complete manure, and must be supplemented by phosphates, if it is to be used alone. The incomplete nature of urine as a manure constitutes a strong argument in favour of its being applied along with the solid excreta, which contain, as we have seen, considerable quantities of phosphoric acid. It is on this account that the drainings of rotten manure-heaps are more valuable, from a manurial point of view, than urine itself, since these contain the soluble portion of the phosphates in the solid excreta.[135] The urine of all animals, however, is not equally poor in phosphates. In the case of flesh-eating animals, such as the dog, the urine is found to contain them in considerable quantities. The above tables show that the most valuable urine, weight for weight, is that of the sheep, as it contains the largest amount of alkalies (including potash) and nitrogen; that the urine of the horse comes next; then that of the cow; while, as has already been pointed out, that of the pig is the poorest.