SHEEP diseases: causes, nature and prevention. 211 
Deficiency in this salt means impaired tissue nutrition; excess of 
it means excessive fluidity of the blood, increased activity of the 
kidneys, by which it is excreted, and dropsies. If the excess per¬ 
sists, defibrination of the blood follows and important forms of 
skin eruption are produced; the kidneys too become organically 
deranged. 
The phosphates are absolutely necessary for the building up 
and nourishment of the bones and teeth; and if they are not sup¬ 
plied in due quantity, the former become soft and thus you have 
produced the various forms of bone softening, such as rickets and 
a tendency to fractures, as is sometimes seen in pregnant mares. 
Moreover, the teeth are imperfectly or slowly developed, and 
when developed tend to decay, and thus you have the late den¬ 
tition (cutting of teeth) common to animals reared on poor lands, 
and the cases of rotten teeth (caries) which are so often seen under 
similar conditions. 
Phosphorus is a constituent of nerve matter, and neither can 
growth go on nor can the functions of the brain be performed 
without it; and it must be remembered that animals cannot make 
up for deficiency in phosphorus in their ordinary food in the same 
way as mao does by eating fish. 
But while phosphorus in due proportion is necessary and ben¬ 
eficial, not only it, but phosphates also, in my opinion, may be¬ 
come baneful. Physiologically we know that phosphorus pos¬ 
sesses the property, if given in excess, of dissolving and breaking 
up the blood cells, of causing very rapid fatty degeneration of 
the coats of the blood-vessels and of such important organs as the 
liver and of degrading the colloids of the blood: as a result of 
this, we get spontaneous flowing out of the blood (hemorrhages) 
into the tissues, and the passing out of albumen and broken-up 
red cells, with their coloring matter, with the urine. Superphos¬ 
phate of lime also possesses the same properties, as was well illus¬ 
trated some years ago in the case of cattle depastured on land 
near Liverpool which had been recently topdressed with this 
agent; the case came under the observation of Mr. Welsby, 
F.B.C.V.S., West Derby. 
Without iron no animal could exist for one moment, and small 
