STAINS, ETC. 



diluting, pass 'he solution through filter-paper. For 

 injection the fluid may be used pure. It may also be 

 combined with gelatin as follows : Warm the solution 

 almost to boiling, and gradually add a warm, thin 

 solution of gelatin until coagulation begins ; then 

 strain through wet flannel. Hoyer's Lead-chromate 

 Mass. Filter through flannel I volume of a solu- 

 tion of gelatin, I : 4, and add 1 volume of a cold, 

 saturated solution of potassium bichromate ; warm the 

 mixture almost to boiling, and add, gradually, I 

 volume of a cold, saturated solution of neutral lead 

 acetate, also warmed. Cool the mass to the body-tem- 

 perature and inject at once. It flows so freely that 

 even the lymphatics may be injected, and its intense 

 color gives the vessels unusual distinctness. If the 

 solution of lead acetate is added to a hot bichromate 

 solution, an orange-red precipitate is obtained ; if both 

 the solutions are cold when mixed, the precipitate is 

 bright-yellow. Hoyer's Silver-nitrate Yellow 

 Mass. Mix with an equal volume of a 4 per cent, solu- 

 tion of silver nitrate a concentrated solution of gelatin, 

 heat, and add a small quantity of an aqueous solution 

 of pyrogallic acid, which reduces the silver in a few 

 seconds. Add chloral and glycerin as in Hoyer's 

 formula for carmin gelatin. The mass is brown in 

 the larger vessels and yellow in the capillaries. It 

 does not change in alcohol, chromic or acetic acid, or 

 potassium bichromate. Neutralization of a Car- 

 min Mass. Villus Method. The traces of acid 

 mechanically retained in commercial gelatin are elim- 

 inated by placing it in a stop-cock funnel and wash- 

 ing for an hour or more with running water. To test 

 the reaction of the coloring-mass, moisten a strip of 

 dichroic litmus-paper in distilled water, and hold as 

 closely as possible to the injection-mass (which is kept 

 melted on a water-bath) ; it becomes blue at first, but 

 as the acid is added the reaction is less evident, and 

 when the change of color appears very slowly, the 

 addition of the acid should cease. Dichroic Litmus- 

 paper is prepared as follows : A tincture obtained by 

 decoction of cake-litmus is slightly acidified with an ex- 

 cess of sulphuric acid, then heated and agitated with 

 an excess of precipitated barium carbonate and 

 filtered. The solution is exposed to the air in wide 

 vessels until the blue color has given place to a red- 

 dish tint, when strips of white, unsized paper are dipped 

 into it and dried in the shade on stretched threads, in 

 a place free from ammonia vapor. Ranvier's Blue 

 Mass. Soak 5 gm. of Coignet's gelatin for one 

 hour in distilled water, wash it, and place it in a beaker 

 on a water-bath; when it is dissolved add 125 c.c. of 

 a saturated aqueous solution of Briicke's blue, pre- 

 viously heated on a water-bath, and stir vigorously 

 with a glass rod, which should show no granules when 

 withdrawn. Filter through flannel. The precipitate 

 thrown down by the gelatin disappears if the heating 

 be continued. Ranvier's Carmin Mass. Mix in 

 a stoppered bottle 2 to 5 gm. of pure carmin with a 

 little distilled water ; add ammonia, drop by drop, 

 until the liquid is transparent, and shake. Place 5 

 gm. of Coignet's gelatin in distilled water for one 

 hour, wash it in water, and heat it in a beaker over a 

 water-bath. When the gelatin is dissolved, add, stir- 

 ring briskly, the solution of carmin. Make a solu- 

 tion of 2 parts of distilled water to I part of glacial 

 acetic acid, and pour it, drop by drop, into the mass, 

 stirring with a glass rod. Stop adding the acid when 

 the ammoniacal odor disappears and there is a faint 

 acid scent. Filter the mass through new flannel. 

 IV. Glycerin Masses. These are used cold. The 

 addition of amyl nitrite to the mass just before using 

 is advised, to counteract its tendency to stimulate con- 



1385 INJECTION MASSES 



traction of the arteries. The animal may also be 

 anesthetized with a mixture of ether and amyl nitrite. 

 Beale's Acid Blue Mass. Dissolve 0.5 gm. of po- 

 tassium ferrocyanid in 30 c.c. of glycerin, and IO drops 

 of tincture of iron sesquichlorid in 30 c.c. of glycerin, 

 and add the latter solution, drop by drop, to the 

 former. Then add 30 c.c. of water and 3 drops of 

 strong hydrochloric acid. If desired, 8 c.c. of alcohol 

 may be added. This is said to be an admirable 

 formula. Beale's Blue Mass. Dissolve 1.8 gm. 

 of potassium ferrocyanid in 30 c.c. each of water and 

 glycerin. Add to 30 c.c. of water 4 c.c. of tincture 

 of ferric chlorid. Gradually, and with agitation, add 

 the iron solution to the potassium solution. Then add 

 slowly 30 c.c. of alcohol and 60 c. c. of water, the mix- 

 ture being constantly shaken. Injected specimens 

 should be preserved in acidulated glycerin, or the color 

 may fade. Beale's Carmin Mass. Dissolve in a 

 little water, with about 5 drops of ammonia, 0.4 gm. 

 of carmin, and add 15 c.c. of glycerin; then add 

 gradually, with agitation, another 15 c.c. of glycerin 

 with 8 or 10 drops of acetic acid or hydrochloric acid . 

 Test with blue litmus paper and add acid until the 

 reaction is decidedly acid. Add another 15 c.c. 

 of glycerin, 5 c.c. of alcohol, and 25 c.c. of water. 

 Robin's Cold-flowing Masses. 1. Carmin. Rub 

 up 3 gm. of carmin in a mortar with a little water 

 and enough ammonia to dissolve the carmin, add 50 

 c.c. of glycerin, and filter. Add a 10 per cent, solu- 

 tion of acetic acid in glycerin, drop by drop, until a 

 slightly acid reaction is obtained. 2. Prussian Blue, 

 (a) Potassium ferrocyanid (sat. sol.) 90 c.c, gly- 

 cerin 50 c.c. ; (b) liquor ferri perchloridi, 8o°, 3 c.c, 

 glycerin 50 c.c. Mix a with b slowly. 3. Green. 

 A saturated solution of potassium arsenite 80 c.c, and 

 glycerin 50 c.c, is mixed with a saturated solution of 

 copper sulphate 40 c.c, and glycerin 50 c c 4. 

 Mahogany-red. [a) Potassium ferrocyanid (concent, 

 sol.) 20 c.c, glycerin 50 c.c; (b) copper sulphate 

 (concent, sol.) 35 c.c, glycerin 50 c.c. Mix a and 

 b slowly, with agitation, and add to the vehicle at the 

 moment of injecting. 5. Yellow, (a) Cadmium sul- 

 phate (sat. sol.) 40 c.c, glycerin 50 c.c; (b) sodium 

 sulphid (sat. sol.) 30 c.c, glycerin 50 c.c. Mix a 

 with b, with constant shaking. V. Vehicles and 

 Other Masses. Bjeloussow's Gum Arabic Mass. 

 Make a saturated solution of borax in water, and a 

 syrupy solution of gum arabic Mix the two, using 2 

 parts of the latter to I part of the former. Rub up 

 the mass with distilled water, added gradually, and 

 press through a fine cloth, repeating this until the mass 

 is free from clots. It should coagulate in alcohol, and 

 swell to twice its original volume. It must not be 

 combined with cadmium or cobalt. Cold-blooded 

 animals may be injected while alive. Cadmium 

 Mass. a. Forty c.c. of a saturated solution of 

 cadmium sulphate and 50 c.c. of glycerin, b. Thirty 

 c.c. of a saturated solution of sodium sulphid and 50 

 c.c. of glycerin. Mix the two solutions with agitation 

 and combine with 3 volumes of vehicle. Copper 

 Ferrocyanid Mass. a. Twenty c.c. of a strong 

 solution of potassium ferrocyanid and 50 c.c. of gly- 

 cerin, b. Thirty-five c.c. of a strong solution of 

 copper sulphate and 50 c.c. of glycerin. Mix the 

 solutions, with agitation. Combine with 3 volumes of 

 vehicle at the moment of using. Fol's Metagelatin 

 Vehicle. To a solution of gelatin add a slight pro- 

 portion of ammonia, and after heating several hours 

 the mixture no longer coagulates on cooling. This 

 vehicle may be thinned by the addition of weak 

 alcohol, and coloring masses added. Its advantage is 

 that it obviates the necessity of warm injections. The 



