XX INTRODUCTION. 



sizes are to be had from the instrument-makers. But a 

 common brass ear-syringe holding about two ounces answers 

 every purpose, using for cannulae glass tubes of the form 

 shown on p. 48, adapted to the nozzle of the syringe with 

 short pieces of caoutchouc tubing. " Bull-dog " forceps will 

 be found very useful in injecting for clamping any vessels 

 which may have been accidentally cut. 



In large classes where the time of the student is limited, 

 it is usually inconvenient for each one to inject his subject : 

 it is then desirable to have an injected preparation in the 

 room which may be consulted when necessary. For this 

 purpose, a rough dissection which the students are allowed 

 to handle is far more useful than a more elaborate preparation 

 mounted in a bottle. In fact, one may say that the only 

 alcoholic preparations of real use to beginners are those 

 which are simple enough to tell their own tale almost at a 

 glance. The most important, in my opinion, are : — 



a. Preparations of the heart with the origins of the great 

 vessels, either filled with solid injection, or distended with 

 alcohol, the cavities, in the latter case, being cut open. 



b. Preparations of the entire brain with the origins of the 

 nerves, and various dissections of the same organ. 



c. Preparations of the adult urinogenital organs, with the 

 various accessory glands, ducts, apertures, &c., displayed. 



Many other very useful preparations might be mentioned, 

 but the above, as demonstrating important points about which 

 the beginner is certain to experience considerable difficulty, 

 may be considered as the most essential. 



