WAX AXD TALLOW IXJECTIOXS. 141 



§ 346. Wax and Tallow Masses. — Wax Mass. — Beeswax, 2 

 parts ; Canada balsam, 2 parts ; Vermilion, 2 parts. 



Mix the wax and Canada balsam and melt over a water bath. 

 Then grind the vermilion thoroughly in a small amount of mastic 

 varnish, and add it to the mixture. Heat over the water bath for 

 half an hour or more. Tliis mass flows very fineh". Hyrtl, A, 616. 



Tallow Mass. — Tallow, 900 grams ; Magnesia usta (calcined 

 magnesia), 15 grams ; Vermilion, 30 grams. 



Grind the magnesia and vermilion in a small amount of mastic 

 varnish or turpentme, before adding to the melted tallow. Ham- 

 son, A, II., 866. 



§ 347. Practical Working of Wax and Tallo-cy Injections. — 



First. The animal must be w^armed to 38-40° C. This is best done 

 in a large galvanized iron dish that may be covered and the 

 water kept hot by means of a Bunsen burner or in some other 

 way. All the heating should be done in a water bath so that no 

 burning may occur. 



When the animal is warmed through (the time required de- 

 pends on the size of the animal), the canula should be put in posi- 

 tion (§ 358). Warm the syringe thoroughly by filling it with hot 

 water and slowly emptying it. AVarm the mass till it is quite 

 fluid, and stii* it well. If it is not heated above 50° C, it will not 

 burn most mammalian tissues. Fill the syringe with the mass and 

 force it out, to make sure the mass is thoroughly mixed. Then fill 

 the syringe, connect it with the canula in the vessel, and force the 

 mass in rather more rapidly than directed for plaster (§ 359), but 

 the operation should not be so long continued. 



One cannot inject Fishes or Amphibia with wax mass, as Hyrtl has well said, for the 

 heat required to wann the subject and the mass would coot the tissues. For them, f)laster 

 or some other cold flowing mass, or glue which remains liquid at a low temperature, must 

 be us3d. 



After the injection is finished, the animal should remain in a 

 cool place for at least three or four hours before the dissection is 

 commenced. 



§ 348. Choice of Specimen for Injection. — A young adult and 

 lean cat is best. It should be fasting except for special pui-poses. 



§ 349. Time of Injection. — Inject before the rigor mortis comes 

 on. If that is impossible, it is better to put it into warm water 

 (35° C.) for an hour to make the muscles flexible. This is not abso- 



