64 General Principles of Veterinary 3Iedicine, 



another, the ends knotted together to prevent dropping out. 

 They are usually smeared with an irritant salve, and turned 

 every day or two, so as to keep up a constant irritation and 

 discharge from the part. The seton needle used for their in- 

 troduction is about six inches long. 



They act very satisfactorily in some cases of bone disease, 

 but where the lameness is owing to strained sinews or liga- 

 ments they are out of place, as they leave additional thicken- 

 ing. They are also valuable in healing old fistulas, being 

 inserted the whole lengj^i of the canal, and setting up a new 

 and healthy inflammation in its sides. As appropriate oint- 

 ments, the following are recommended for smearing the seton : 



No. 13. Powdered cantharides, 1 part. 



Oil of turpentine, 

 Canada Balsam, of each, 8 parts. 



Digest the cantharides and turpentine together and add the balsam. 



No. 14. Powdefed white hellebore, 1 part. 



Lard, 8 parts. 



Mix at a gentle heat. 



No. 15. Citrine ointment, 3 parts. 



Oil of turpentine, 1 part. 



Mix. 



Or either of the ingredients in this last formula alone will 

 answer very well. 



FIRING. 



The hot iron or the actual cautery is a very useful agent in 

 veterinary practice, and should not be dispensed with or con- 

 demned on mistaken notions of tenderness. In certain dis- 

 eases it cannot be successfully replaced by any other form of 

 counter irritation. It must of course be used with discretion, 

 but any one with experience must have seen it remove pain 

 very rapidly w^hen blisters, etc., have failed to do so. In 

 bone diseases and in many cases of chronic lameness, it is of 

 great benefit. 



