534 OBSTETRIC OPERATIONS. 



So it is that, for nearly all the cutting operations, an ordinary pocket 

 knife or bistoury is sometimes the only instrument employed ; the ope- 

 rator being satisfied if the spring is sufficiently strong to prevent the 

 blade shutting up in the handle when it is used in the uterus. Rainard 

 preferred an ordinary knife with a blunt point and a convex cutting edge ; 

 others use a bistoury cache. Even small pocket-knives of various sizes 

 are utilized for this purpose, and one of Mr. Cartwright's embryotomy 

 knives is not unlike a gardener's large pruning knife. In the use and 

 preference for knives, much must depend upon custom and the expertness 

 of the operator. 



Nevertheless, convenience, safety, and the absence of long experience, 

 demand that proper instruments be devised for this operation ; and this 

 requirement has long been present to the minds of veterinary obstetrists. 

 One of the earliest to introduce a convenient and efficient embryotom 

 was Giinther, who, in his work, published in 1830, figures an instrument 

 which is fixed on the finger by a ring ; the cutting edge of the blade, 

 about two inches long, being somewhat concave. This embryotom has 

 been slightly modified in various ways by different practitioners — some- 

 times having two narrow rings, so as to grasp more of the finger ; at 

 other times having, in addition, a small button on the back of the blade 



Fig. 185. Fig. i86. 



Straight Embryotom. Curved Embryotom. 



for the finger to press upon ; while the blade itself has been made more 

 curved, straighten longer, or like the blade of a fleam. This instrument 

 is the prototype of the ring scalpel invented by Dr. Simpson, of St. An- 

 drews, for opening the skull of the human foetus. Two of these embry- 

 otoms which have been used in England, are shown in the annexed 

 figures (185, 186). An improvement in this instrument is the having a 

 hole at the opposite end of the blade (Fig. 186), through which a piece 

 of cord or tape can be passed and tied round the wrist, to prevent the 

 knife slipping from the finger and falling into the cavity of the uterus. 

 Indeed, this is a wise precaution with all the short instruments introduced 

 into the genital organs, as the contractions of the uterus, struggles of the 

 animal, and the position of the hand, as well as the slipperiness caused 

 by the presence of mucus, etc., only too often render the hold of the in- 

 strument very insecure. The middle-finger of the operating hand is passed 

 through the ring and the other fingers enclose the blade, which is in this 

 way safely conveyed to the part of the foetus which is to be incised. The 

 finger-knife is the most useful instrument in embryotomy. 



Giinther also at this time introduced another form of embryotom, 

 which has likewise continued in use, and has been more or less altered 

 or improved in shape. This consists of a blade, which can be made to 

 slide out of or into a handle, by the thumb of the hand holding it. It 

 can therefore be introduced into or withdrawn from the genital passage, 

 without risk of injury to the maternal organs. The annexed figure (187) 



