192 NON-rNFLASTMATOEY DISEASES OF BONEa. 



aud contaLning a small quantity of fut BencatJi tiie oarUlos© 

 the Lone "was found soft, the lamellte very tliln, with the Inter- 

 spaces filled "with a greasy white- looking substance, fat, aud the 

 extremity of the bone generally non-vascular. The synovial 

 membrane was much tliiclcened in some Joints, hut tlie quantity 

 of synovia in aU was small, dark in colour, and in some cases 

 mixed with dots of blood. The periosteum of all the boues 

 was easily stripped ofif, and the bones themselves were soft 

 and easily cut with the knife. Within the bonea the cancelli 

 were filled with a red gelatinous substance. The libs, die 

 vertebrae, and all the irregular and flat bones were in the same 

 condition. The shafts of the long bones were exti-ynally but 

 little different from healthy ones; but on making a longitu- 

 dinal section of them, the medullary canal and the jjancellated 

 spaces near their extremities were dark red in colour, from con- 

 gestion of tie vessels and extravasation of blood into the 

 areolar spaces. In otber parts a peculiar fat was found, giving 

 8 paleness to the colour ; and the bones wei-e near their ends so 

 filled that the cartilage appeared to be of a palish yeEow colour, 

 and was velvety and Rightly greasy to the touch. 



In some cases the teeth do Qot escape ; the crusta i)etrosa 

 being evidently Increased in tluckness, and more spongy than 

 natural Ko class or breed of horses seems exempt from this 

 disease, as I have records of cases of it in carriage horses, in 

 ponies, and in thorougb-bred ones, whilst Professor Varnell's 

 cases belong to the cart breed. It seldom affects horses above 

 six years old ; frequently, indeed, the animals have ranged from 

 two up to four years old ; but my later observation teaches me 

 that very old horses are not exempt from the diseasa Professor 

 Yamell enters into a very lucid examination of the cause, and 

 leaTes one with the impression that it is due to food or water 

 deficient in the salts of lime. Experience, however, seems to 

 prove that the absence of lime is not a constant factor so far 

 as the life-histoly of the animal can bo traced, nor can it be 

 conclusively proved to be due to any peculiar geological 

 formation or particular locality. One of Mr. Eobinson of 

 Greenock's cases was attacked while in London, during the 

 summer season, with symptoms analogous to those of rheuma- 

 tism, and all his cases were well-cared-for animals. It has been 

 witnessed in Shetland ponies. In America the disease is called 

 Big-head, from the peculiar swollen state of the jaws; it is 

 there supposed to be dug to the feedincr uDon maire, and it has^ 



