MODERN METHODS OF EXAMINATION. 73 



Dissolve the ferrocyanide in 1 ounce of water and glyc- 

 erin, and the muriated tincture of iron in another ounce. 

 Add the latter very gradually to the other, shaking often ; 

 then gradually add the alcohol and water. 



Beetle's Finest Blue. 



Price's glycerin, 2 ounces. 



Tincture of perchloride of iron, . . .10 drops. 

 Ferrocyanide of potassium, .... 3 grains. 

 Strong hydrochloric acid, ..... 3 drops. 

 Water, 1 ounce. 



Mix the tincture of iron with 1 ounce glycerin and the 

 ferrocyanide, after dissolving in a little water, with the 

 other ounce. Add the iron to the other solution gradu- 

 ally, shaking well. Lastly, add the water and hydro- 

 chloric acid. Sometimes about 2 drachms of alcohol are 

 added. 



Miiller's Blue. This is made by precipitation of soluble 

 Prussian blue from a concentrated solution by means of 

 90 per cent, alcohol. 



Beetle's Carmine. Mix 5 grains of carmine with a few 

 drops of water, and when well incorporated, add 5 or 6 

 drops of liquor ammonia. To this add J ounce of glyc- 

 erin, and shake well. Another J ounce of glycerin con- 

 taining 8 or 10 drops of acetic or hydrochloric acid is 

 gradually added. It is then diluted with J ounce of glyc- 

 erin, 2 drachms of alcohol, and 6 drachms of water. 



Nitrate of Silver Injection. For demonstrating the struc- 

 ture of the bloodvessels, the animal is bled, and a solution 

 of 0.25 to 1 per cent, of nitrate of silver, or a mixture of 

 gelatin with such a solution, is used. 



5. PRESERVATIVE FLUIDS. 



Canada Balsam. This is perhaps the most common 

 medium used. When an object is not very transparent, 

 and drying will not injure it, balsam will do very well, 



