ON MINUTE INJECTIONS. 159 



sected for this purpose, dried, and varnished, and form excellent 

 illustrations of anatomical lectures. 



When, however, it is desired to demonstrate the capillaries, 

 a finer injection and more delicate manipulation are required. 

 Indeed, it is so difficult an art, and success is so dependent on 

 the combination of various circumstances, that the most ex- 

 perienced are often defeated in their efforts. Yet some of the 

 finest injections I have ever seen were made by those who 

 attempted it for the first time. 



For minute injection (as it is called), the most essential in- 

 strument is a proper syringe. This should be made of brass, of 

 such a size that the tip of the thumb may press on the head or 

 handle of the piston-rod when drawn out, while the body is 

 supported by two of the fingers of the same hand. 



Fig. 50 represents a syringe, with which I have succeeded 

 in making some excellent preparations. A is the cylindrical 

 brass body, on the top of which screws the cap, B, a leather 

 washer being interposed to render it more air-tight. C is the 

 piston, which is of brass, covered with wash-leather. The 

 bottom of the syringe, D, also unscrews, for convenience of 

 cleaning. E is a stop-cock, on the end of which another stop- 

 cock, F, fits closely. On the end of this, one of the injection- 

 pipes, G-, which are of different sizes, may be placed. The 

 transverse wires, across the injection-pipes, are designed for the 

 better security of the pipe in the vessel into which it is fixed ; 

 the thread being tied behind them so that it cannot slip for- 

 wards. A half-dozen pipes, at least, are necessary to accom- 

 pany each instrument. 



In addition to the syringe, a large tin vessel to contain hot 

 water, with two or three lesser ones fixed in it for the injec- 

 tions, will be found useful. 



For very minute injections, as in the Mollusca, &c, a caout- 

 chouc bottle, with a capillary steel tube mounted in wood, 



