138 



ANATOMICAL TECHNOLOGY. 



Barrel. The barrel of the syringe is the large cylindrical part in which the piston fits. 



The injecting mass is drawn into it by pulling the piston in the direction of the handle. 



Canuia, 



Pig. 85.— White-Metal Syeingb with Top Unsckbwbd and Piston 



Removed ; x .3. 



Canuia. — The canuia is the smaller part which serves to connect the syringe with the 

 object to be injected. 



Handle. — The handle is a continuation of the piston. It projects from the barrel, and 

 by it the piston is moved. 



Piston. — The piston of a syringe is within the barrel. Its end should be packed with 

 leather, as shown in the figure, so that it will fit very closely. 



Canuia or Nozzle. — The canuia serves to 

 connect the syringe with the object to be in- 

 jected. The end should be cut oflf obliquely. 

 It is then like a wedge, and may be inserted 

 into the vessel much more easily than one 

 cut squarely oif. 



The caliber of the canuia should be as 



\ ^^ P great as can be put into the vessel to be in- 



" jected. For plaster injections (§ 341) the 



canuia should not be less than 1 mm. at its 

 narrowest point. 

 A. — Metal canuia with lateral arms at the end next the syringe, and a slight shoulder 

 at the small end. 



B. — A glass canuia cut ofi' obliquely at its small end. 

 C. — A glass tube drawn out for two canulae. 



§ 340. To prepare glass canulse, take a glass tube about 6 mm. 

 in diameter and from 8-10 cm. in length, and heat its middle evenly 

 in a Bunsen flame. When the glass is softened, draw the two ends 

 apart until the tube is sufficiently reduced in caliber in the middle ; 

 then after cooling make a fine scratch with a file as shown in C, and 

 the two may be broken apart. When separated, grind the end first 

 on a fine file with water to make it oblique as in A and B, and 

 finally on the fine oil stone to make it smooth. Heat the larger end 

 in the flame to round the sharp edges. 



