INJECTION. 



[ 427 ] 



INJECTION. 



inclined board, and fitted to the pipe, the 

 stopcock being turned off. The rod and 

 strings are next adjusted, and, a suitable 

 weight being added, the stopcock is very 

 slowly turned on, and the effect watched. 

 If the handle of the syringe does not move, 

 more weight must be added, the stopcock 

 always being turned off when this is about 

 to be done. 



A great advantage of this apparatus is, 

 that it sets at liberty the hands, so that an 

 escape of injection may be arrested, or fresh 

 warm water added, without interruption of 

 the process. 



Other automatic methods have been pro- 

 posed, as that of Rutherford, which is 

 this : 



A large jar of water is attached to a 

 pulley, so that it can be elevated to any 

 height. A long elastic tube with a stopcock 

 is connected with the interior of the jar, 

 near its bottom, so that the water may flow 

 out when required. The other end of this 

 tube transmits the water into a large 

 Woulfe's bottle having three apertures. 

 The water flows in by one aperture, through 

 a glass tube which passes to the bottom 

 of the bottle. The air is thereby forced 

 through the other two apertures, one com- 

 municating with a mercurial manometer for 

 indicating the pressure, the other transmit- 

 ting the air through an elastic tube to a 

 second Woulfe's bottle containing the injec- 

 tion. This bottle has two apertures. The 

 air is forced upon the surface of the liquid, 

 and a glass tube, reaching nearly to the 

 bottom of the bottle, transmits the injection 

 to an elastic tube joined to a glass or metal 

 nozzle placed in the vessel. Any number 

 of Woulfe's bottles may be added, so that 

 different injections can be thrown in at the 

 same time. The pressure can be regulated 

 with the greatest nicety. 



When it is not required to fill the capilla- 

 ries, but only the smaller arteries or veins, 

 the colouring-matters need not be prepared 

 by double decomposition, and the following 

 substances may be used : 



Red. Size 1 lb., vermilion 2 oz. 

 Yellow. Size 1 lb., King's yellow 



(orpiment) or chrome-yellow 2| oz. 

 White. Size 1 lb., flake-white 3| oz. 

 jS/we. Size 1 lb., fine blue smalt 6 oz. 

 Black. Size 1 lb., lamp-black 1 oz. 



Injections made with transparent solu- 

 tions are now largely used, the objects being 

 viewed with high powers, by transmitted 



light. Fine gelatine is usually employed, 

 and is dissolved in water over a water-bath, 

 the colouring-matter already in solution 

 being then added, and the mass introduced 

 into a Woulfe's bottle, which must be im- 

 mersed in a warm water-bath. The injec- 

 tion takes long to do; and the warmth must 

 be kept up. The colouring matters usually 

 employed are prussian blue and carmine 

 the latter not in a state of complete solu- 

 tion, but partly precipitated by the addition 

 of a little weak acid from its alkaline solu- 

 tion. Thiersch, whose transparent injec- 

 tions are wonderful, uses a transparent yel- 

 low, and green, the former from chroniate 

 of potash and nitrate of lead, and the latter 

 from a mixture of this with blue. Beale, 

 in order to avoid the injecting of warm 

 fluids, uses colouring-matter, water, glyce- 

 rine, and traces of hydrochloric acid ; after- 

 wards the injected mass is placed in absolute 

 alcohol. 



Carter's carmine injection is made thus : 

 dissolve 60 grains of pure carmine in 120 

 grains of Liq. Ammon. fort., and filter if 

 necessary; mix with this 1| oz. of hot 

 solution of gelatine (1 to 6 of water) ; mix 

 another oz. of the gelatine solution with 

 86 minims of glacial acetic acid, and drop 

 this little by little into the solution of car- 

 mine, stirring briskly the whole time. Dry, 

 or harden in solution of chromic acid ; cut 

 with a sharp razor, and mount in Canada 

 balsam. 



Beale's fine blue injection is made with 



Glycerine 1 oz. 



Spirit of Wine 1 oz. 



Ferrocyanide of potassium .... 12 gr. 



Tinct. or sol. of perchlor. iron . . 1 or. 



Water 4 oz. 



Dissolve the ferrocyanide in 1 oz. of the 

 water and the glycerine, and the iron in 

 another oz. Mix gradually, adding the iron 

 to the ferrocyanide. Then add the spirit 

 and the rest of the water. 



For very fine injections, the mixture may 

 be diluted with 3 oz. of glycerine, and half 

 the quantity of ferrocyanide and iron used. 



The ferridcyanide of potassium is often 

 used, forming Turnbull's blue, which is 

 brighter and less liable to fade. This is 

 made with ferridcyanide of potassium 

 10 grs., sulphate of iron 5 grs., glycerine 

 2 oz., water 1 oz., and alcohol 1 drachm. 



Numerous other fine injections are de- 

 scribed by Beale and Frey. 



