16 T. CHARTERS WHITE ON THE INJECTION OF 



similar circumstances offered to the Club, in the hope of making it 

 appear to the members not such a difficult task for any amongst 

 us to take up the subject of injection. Of course in injecting such 

 animals as Fish or Mollusca, more difficulty will at first be experi- 

 enced than with a small Mammal; but when once the student 

 attains tolerable facility in the use of the apparatus I will presently 

 describe, no great difficulty will present itself in injecting any mem- 

 ber of the Animal Kingdom. 



I have placed under my microscope this evening an injected pre- 

 paration from the small intestine of the Guinea pig, not as an 

 example of perfect injection, but to show more clearly what I 

 mean by having a regard to the other elements of a structure 

 besides the vessels; and I will describe the modus operandi by 

 which I produced that preparation, and advise such of you 

 who may wish to follow up this branch of work to undertake it 

 with the full assurance that what I have but imperfectly performed 

 would, with more time and attention than I could give, be attended 

 by far more beautiful and instructive results. I do not wish to say 

 anything relative to opaque injections, because I have had no 

 personal experience in their production, but I shall confine myself 

 to the making of transparent injections with cold injection fluid, 

 although I believe that very beautiful preparations could be made 

 by the amateur with a little attention to temperature, by using a 

 warm injection of gelatine stained with carmine. With regard to 

 the instrument to be employed, I may say that although a syringe 

 is generally recommended to force in the injection, I found it 

 attended by so much unsteadiness and fatigue, followed often by 

 bursting of a vessel and consequent extravasation, that, however 

 deftly it may be employed by the professional injector, I gave it 

 up, and resorted to gentle and continuous pressure by a falling 

 column of the fluid injection. The injection I used was Beale's 

 Blue fluid, and as this requires a little care in its preparation, 

 directions for its proper combination may be fitly inserted at this 

 stage of the description. The formula I have found most satisfactory 

 is that given by Dr. Beale in " How to Work with the Microscope," 

 at page 114, and is as follows : — 



Glycerine, 2 ounces. 



Wood Naphtha, 1& drachms. 



Spirits of Wine, 1 ounce. 



Ferrocyanide of Potassium, 12 grains. 



Tincture of Sesquichloride of Iron, 1 drachm. 



Water, 3 ounces. 



