180 



CLASS VI. 



DISEASES OF BONES. 



RICKETS (RACHITIS). 



Rickets is very like to tabies in all its causes, and also in some 

 of its appearances and effects : it is common to the same breeds, 

 and is both occasional and hereditary. It is occasional when it 

 meets with the circumstances of confinement, bad air, filth, and 

 unwholesome food, or the milk of an unhealthy mother. Many 

 whelps are horn with the predisposition among the fancy breeds 

 in the confined parts of great cities andjarge towns, particularly 

 pugs and the smaller sort of bull dogs : there is also a breed of 

 wry-legged terriers that without doubt originated in ricketty spe- 

 cimens which were afterwards cultivated for particular purposes, 

 as for rabbit-hunting, &c. The affection often appears soon after 

 birth ; and shews itself by the slow development of the body, ex- 

 cept in the head, belly, and joints, all of which enlarge at the ex- 

 pense of the rest of the parts : particularly it attacks all the joints 

 of the extremities ; these swell into protuberances, probably from 

 a sympathy in the constitution to make up, by bulk, what the 

 bones want in ponderosity, but which is not effected ; for, deprived 

 of their earthy solidifying principles, they yield to the superin- 

 cumbent weight, and the cylindrical ones particularly become 

 crooked. Cleanliness, good air, free exercise, and wholesome 

 food, will commonly prevent it in the future breeds of such dogs 

 as have shewn a disposition to it. As a cure, an invigorating diet 

 added to these, with the occasional use of tonic bitters if the appe- 

 tite fails, or the digestion should appear defective, will answer the 

 intention. 



Unconsolidated fracture, — The phosphate of Hme, or osseous 

 matter which should form the callus of bones, in some cases i<? 

 never deposited between their fractured ends, and a mere cartila- 

 ginous union remains. It is evident this is, in fact, a disease of 



