-236 INJECTIONS. 



I believe this will be found useful for many purposes, espe- 

 cially for work amongst invertebrates, as well as for lympha- 

 tics, juice-canals, and the like. 



Celloidin Masses. 



486. Schiefferdecker's Celloidin Masses (Arch. Anat. it. Phys., 

 1882 (Anat. Abth.), p. 201). (For Corrosion preparations). ' 

 1. Asphalt-celloidin is the best of these injections. To pre- 

 pare it 



Pulverise asphalt in a mortar, and put it for twenty-four 

 hours into a well-closed vessel with some ether, shaking occa- 

 sionally. After the twenty-four hours pour off the ether into 

 another vessel, and dissolve in it small pieces of celloidin until 

 the solution is of the consistency of one of the thicker fatty 

 oils. (The undissolved asphalt may be employed for colouring 

 a fresh quantity of ether, in which substance it is not very 

 soluble.) 



2. Vesuvianin Celloidin Brown Injection. Make a concen- 

 trated solution of Yesuvianin in absolute alcohol and dissolve 

 celloidin in it. (This colour is not fast.) 



3. Opaque Blue Celloidin Injection. Dissolve celloidin in 

 equal parts of absolute alcohol and ether, and add pulverised 

 Berlin blue. 



4. Opaque Red Celloidin Injection. Proceed as above (3), 

 taking pulverised cinnabar instead of Berlin blue. The two 

 last pigments should be rubbed up in a mortar with a little 

 absolute alcohol, and the paste added to the celloidin-mass. 

 Be careful not to take more pigment than is absolutely neces- 

 sary, or the injection will become brittle. To filter (if this 

 be thought necessary), strain the mass through flannel wetted 

 with ether. Syringes must be free from grease, which would 

 render the mass brittle. The nozzles to be filled with ether. 

 Inject quickly, as the mass soon sets on contact with watery 

 tissues. Clean syringes and nozzles with ether. 



Corrosion of the Preparations. The injected organs are 

 thrown into unrectified hydrochloric acid, where they remain 

 (the acid being changed from time to time if necessary) until 

 all the tissues are destroyed. Wash under a slow stream of 



