STAINS, ETC. 



1384 



INJECTION MASSES 



hours, wash thoroughly in water, and harden in alcohol 

 of gradually increasing strength. Sections may be 

 stained in hematoxylin or safranin. Silver Nitrate. 

 Used in the study of epithelia. Solutions of 0.5 to 2 

 per cent, are employed, and fix rapidly. Wash out in 

 distilled water. Weak solutions do not interfere with 

 subsequent staining. 



INJECTION-MASSES. 

 These are composed of a dye combined with some 

 suitable substance, technically termed, respectively, 

 the coloring-mass and the vehicle, and are used for in- 

 jecting gland-tubes and blood-vessels. I. Aqueous 

 Masses. Emery's Carmin. Add, with continual 

 stirring, acetic acid to a 10 per cent, ammoniacal solu- 

 tion of carmin until the color of the fluid is blood-red 

 from incipient precipitation of the dye. The 

 clear solution is poured off and injected cold, and the 

 specimens are thrown at once in strong alcohol to fix 

 the carmin. This fluid is for the injection of fishes. 

 Letellier's Ammonium Vanadate and Tannin. 

 Make a solution of ammonium vanadate in warm 

 water and of tannin in hot water. For use, mix the 

 two solutions according to the tint desired. The walls 

 of vessels are stained black. Miiller's Berlin 

 Blue. Precipitate a strong solution of Berlin blue 

 with 90 per cent, alcohol. The fluid is neutral and 

 the precipitate finely divided. Taguchi's Indian 

 Ink. Rub up on a hone Japanese or Chinese ink, 

 until a fluid is obtained that does not run when 

 dropped on thin blotting-paper or form a gray circle 

 round the drop. Inject until the preparation appears 

 black, and then put it into some hardening fluid, not 

 pure water. This is useful for Invertebrata, lymphat- 

 ics, and juice-canals. II. Celloidin Masses. 

 Schiefferdecker's Masses. For corrosion-prepara- 

 tions. 1. Place pulverized asphalt in a closed vessel 

 with ether for twenty-four hours, and shake occasion- 

 ally. Pour off the ether into another vessel, and dis- 

 solve in it small pieces of celloidin until the solution 

 is like the thicker fatty oils. The undissolved asphalt 

 may be used to color fresh ether. 2. Vesuvianin- 

 brcnvn. Dissolve celloidin in concentrated solu- 

 tion of vesuvianin in absolute alcohol. This color is 

 not fast. 3. Opaque Blue. Add pulverized Berlin 

 blue to celloidin dissolved in equal parts of absolute 

 alcohol and ether. 4. Opaque Red. Rub up in a 

 mortar pulverized cinnabar with a little absolute 

 alcohol, and add the paste to celloidin dissolved in 

 equal parts of absolute alcohol and ether. Too much 

 pigment will make the injection brittle. Strain the 

 mass through flannel wet with ether. Clear the syringes 

 and nozzles with ether to free them from grease. 

 Corrosion of the Preparations. Throw the injected 

 organs into unrectified hydrochloric acid, and let them 

 remain in it until all the soft parts are destroyed, 

 changing the acid occasionally, if necessary. Wash 

 under a slow stream of water, leave for some weeks 

 in water, rinse, and put in glycerin or in equal 

 volumes of glycerin, alcohol, and water. Artificial 

 gastric juice is also excellent for corrosion. III. Gela- 

 tin Massks. Briicke's Blue Mass. Take a 10 per 

 cent, solution of potassium ferrocyanid, and precipitate 

 it with so much of a dilute solution of iron sesqui- 

 chlorid that the weight of the dry chlorid employed 

 shall be -^ or \ that of the ferrocyanid. Wash the 

 precipitale on a filter with the filtrate until only a 

 clear-yellow liquid runs off, then wash with water 

 until the water begins to be blue. Dry the precipitate, 

 press it between blotting-paper in a press, break the 

 mass in pieces, and dry in the air. Carter's Carmin 

 Mass. Rub up 4 gm. of carmin in a little water in 



a mortar, and add enough water to bring the measure 

 up to 45 c.c. Add 8 c.c. of strong ammonia, and 

 stir until the carmin is dissolved. Glacial acetic acid, 

 6 c.c, is then added, drop by drop, with continuous 

 stirring, and finally the gelatin, 60 c.c. of a I : 6 solu- 

 tion in water. Fearnley's Modification : Cut up 7 

 gm. of Coignet's gelatin, and soak it in 50 c.c. of 

 water 4 to 5 hours. Rub up in a mortar with a little 

 water 3 gm. of carmin, and add 6 c.c. of strong am- 

 monia ; after standing for 2 hours, pour it in a bottle, 

 rinsing the mortar with 30 c.c. of water. Place the 

 gelatin and unabsorbed water on a water-bath to melt. 

 Add about 6 c.c. of glacial acetic acid to the carmin 

 solution (stop the acid when the color changes to 

 crimson), and stir it into the gelatin. Cover the mass 

 with methylated spirit, and keep it in a cool place. 

 For use, dissolve it on a water-bath, and filter through 

 fine flannel wrung out of hot water. Fol's Blue 

 Mass. A Modification of Thiersch ' s Formula, a. 

 To 120 c.c. of a cold saturated solution of iron sul- 

 phate add 300 c.c. of warm gelatin solution. b. To 

 600 c.c. of the gelatin solution add 240 c.c. of a 

 saturated solution of oxalic acid, and then 240 c.c. of a 

 cold saturated solution of potassium ferricyanid. Pour 

 the first mixture gradually into the second, shaking 

 vigorously, and warm for fifteen minutes over a boiling 

 water-bath. When the mass has set, press it through 

 netting into strings, wash in running water, and dry 

 on prepared paper, without remelting. For use, swell 

 the strings in cold water, and warm with enough oxalic 

 acid for complete solution. Fol's Brown Mass. 

 Soak 500 gm. of gelatin in 2 liters of water in which 

 140 gm. of salt have been dissolved. Melt the mass 

 over a water-bath and add, gradually, with vigorous 

 shaking, 300 gm. of silver nitrate in a liter of water. 

 Press the mass out through netting, stir it up, in clear 

 daylight, with a mixture of 1^ liters of a cold saturated 

 solution of potassium oxalate and 500 c.c. of a cold 

 saturated solution of iron sulphate. When the whole 

 mass is black, wash for several hours, remelt, and 

 pour on paper. Fol's Carmin Mass. Soak in 

 water for a couple of hours one kilog. of Simeon's 

 photographic gelatin, pour off the water,melt the gelatin 

 over a water-bath, and add one liter of a solution of 

 carmin made as follows : Dilute a strong solution ol 

 ammonia with 3 or 4 parts of water and mid 

 carmin to saturation, removing the excess by filtration 

 just before adding the liquid to the gelatin. Add to 

 the mass enough acetic acid to turn the dark-purple 

 color to a blood-red hue, and when firm, cut it in 

 pieces. Tie up the pieces in fine netting, and com 

 press them with the hand under water acidulated with 

 o.l per cent, of acetic acid. The mass is driven out 

 in fine strings, which are washed for several hours in 

 a sieve in running water, then remelted, and poured 

 on large sheets of parchment-paper soaked with parol 

 fin, and dried in an airy place. Separate the mass 

 from the paper and cut into long strips. For use. 

 soak them a few minutes in water and melt th 

 a water- bath. Frey's White Mass. Place 1 2j 

 185 gm. of a cold saturated solution of barium chlorate| 

 in a tall, glass cylinder, and add sulphuric acid ven 

 carefully, drop by drop. Allow the precipitate t< 

 settle for twelve hours ; then decant almost all ol the 

 supernatant liquid. The remaining mucilaginous mas*.| 

 containing the precipitate, is to be mixed with 

 part of concentrated gelatin solution, [njecti 

 may be preserved in chromic acid. Hoyer's Blue 

 Mass. The filtered and washed precipitate of solul [« 

 Berlin blue is placed in a little water on a Graham 

 dialyzer, and the external water changed until th' 

 solution begins to pass through the parchment. Afl ! 



