SYRINGE (from 15pryt, a pipe), a portable hydraulic instrument of the pump kind, commonly employed for the forcible ejection of fluids. In its simplest form it consists of a cylindrical tube, with a perforated nozzle at one end, and a piston, to the rod of which a handle is attached. The tube being held in the left hand, with its nozzle immersed in water, the piston is drawn to the upper end of the tube by the right hand. The pressure of the atmosphere upon the surface of the water causes it to follow the piston, so that the syringe becomes filled with water. The instrument is then removed from the vessel of water, and, by pushing the piston back towards the nozzle, its contents may be ejected with a force proportionate to the power applied to the piston.
The use of syringes for extinguishing fires is alluded to under FIEE ENGINE. They were usually made of brass, and held from two to four quarts each. Those of the former capacity were about two feet and a half long, and one inch and a half in diameter, that of the nozzle being half an inch. They were furnished with handles on each side, and every syringe required three men to work it. The large syringes used for horticultural purposes might, in many cases, be used with advan tage on the first discovery of a fire, when a very small quantity of water, promptly applied and accurately directed, might prevent serious mischief. Garden-syringes are made either to throw water in a com pact jet, from a simple nozzle with one perforation, or to distribute it in the form of a shower, from a rose perforated with a number of small holes. In the latter case it is usual to add a nozzle of compara tively large bore, through which water is allowed to enter, although a self-acting valve prevents it from returning the same way. Several different caps may be fitted to the same syringe; those for throwing jets having the injection and ejection nozzles side by side, while those for producing showers have the injection nozzle in the centre of the rose. Syringes may also be applied with advantage in washing car
riages, cleaning windows, and for other useful purposes. Mr. Baddeley has introduced many improvements in garden-Syringes.
In medicine and surgery syringes of various kinds are employed in administering clysters; in injecting fluids into, or removing them from, the stomach or bladder ; injecting liquids into wounds ; and injecting coloured liquors or melted wax into veins, &c., iu anatomical prepara tions. The application of the syringe as a stomach-pump is peculiarly important. In this case a flexible tube is put into the mouth of the patient, with a guard between the teeth to preserve it from injury, and a branch pipe is added to supply the syringe with liquid from a vessel, when it is used for injection, and to afford a channel for the escape of the abstracted liquid when the syringe is employed to empty the stomach. By an ingenious arrangement of valves, the same instrument may be so modified as to act equally well in either way. One method of using such an instrument is, first to inject a diluent into the stomach, and then to pump it back again, together with the injurious matter which it is desired to remove. Another plan is to inject a fluid into the stomach until an involuntary discharge takes place through the mouth, and to continue the operation until the stomach is cleansed, this being indicated by the fluid returning unchanged.
Mr. James Harris, of Plymouth, in 18'22, devised a method of pre serving oil-colours for painting in syringes formed of tin, or of brass tinned internally. A similar contrivance, in which the details differ from Mr. Harris's, although the same principle, that of propelling the piston by means of a screw, is preserved, has been brought into use; but tubes of very thin metal, from which the colour is expressed by collapsing the tube between the finger and thumb, without the use of a piston, have nearly superseded all other contrivances.