FEACTUEE OF THE NAVICULAR BONE. 139 



Upon examination, the navicular bone was found fractured, 

 and the fracture reunited by false joint, I am of opinion that 

 the fracture had occurred immediately after the operation, and 

 that union had taken place very shortly afterwards. The case 

 was under very favourable circumstances, being driven in the 

 cart by a very careful old man, and never pushed beyond a 

 walking pace. 



The OS pedis is fractured in various ways : — 1st. By violence, 

 as when the calkins of the shoe are entangled in a rail-v\'ay point, 

 the horse falling, and a large portion of the crust becoming de- 

 tached, and at the same time the bone being lacerated. 2d. 

 From the falling of heavy weights upon the feet. M. By con- 

 cussion ; but before this form of fracture can occur the bone must 

 be in a fragile condition, resulting from chronic laminitis. 4:th. 

 From the prick of a nail in shoeing. This fracture may be 

 immediate, or a piece of bone may become detached from the 

 pressure of the nail, thus constituting a fracture by partial 

 necrosis. 



The first kind may be considered beyond treatment, unless, 

 indeed, the fracture be very slight, and easily removed. The 

 proper treatment will be the removal of all detached horn and 

 fragments of bone, the application of poultices, and the ad- 

 ministration of febrifuges, with rest in the slings until the fever 

 subsides. 



It is curious to observe how soon a portion of foot stripped of 

 its crust is sheathed and coated over by the horny secretion of 

 the sensitive laminae ; in a very few days, if the laceration of 

 the soft tissues has not been great — where the horn is merely 

 stripped off — it will be found that the soft structures are covered 

 over by a layer of protecting horn, which prevents further irri- 

 tation, and enables the patient to move the foot with comparative 

 ease. Had the advocates of the hypothesis, that the horny 

 laminte are secreted by the coronary substance, only remembered 

 what they must have observed in the course of their practice, 

 they never would have propounded such an absurdity.* After 

 the pain and fever have subsided, the practitioner must deter- 

 mine if a shoe can be applied with advantage or not. If it be 



* Notwithstanding the severe strictures of one critic, who states that the laminae 

 do not secrete horn, I maintain my view that a horny secretion is formed by them 

 independently of the coronary band. 



