45 2 APPENDIX II 



most purposes. For fine injection use a combination of 

 the following: I part of a solution of gelatine, I part to 

 4 parts of water; I part of a saturated solution of lead 

 acetate in water, and I part of a saturated solution of 

 potassium bichromate in water. A mixture of these when 

 hot gives a beautiful yellow injection-mass which, filtered, 

 will pass through the finest capillaries. For different 

 colorings use dry paints, which come in ultramarine blue, 

 vermilion, and green. The gelatine should be thoroughly 

 soaked before the coloring-matter is added. A mistake 

 is generally made in using the injection-mass too thick. 

 One part by weight of gelatine to six or even more parts 

 of water is a good proportion. The gelatine as well as 

 glue-masses should be made in a water-bath, which con- 

 sists of one dish placed within another outer one contain- 

 ing warm water. The mass should be injected warm, not 

 hot, after which the injected specimen is to be placed in 

 cold water until the injecting-mass has set. Glue (the 

 ordinary white kind) can be used for most injections just 

 as the gelatine was used, but should not be so much 

 diluted. All injection-masses should be filtered through 

 a cloth before using. 



Preparing skeletons In general, skeletons are best 

 cleaned by boiling. After most of the flesh has been cut 

 away the skeleton should be boiled in a soap solution 

 until the remaining parts of the muscles are thoroughly 

 softened. The soap solution is made of 2,000 c.c. of 

 water, preferably distilled, 12 grams of saltpetre, and 75 

 grams of hard soap (white). Heat these until dissolved, 

 then add 150 c.c. of strong ammonia. This stock solu- 

 tion is mixed with four or five parts of water, when the 

 mixture is ready for use. The bones after boiling are 

 rinsed in cold water, brushed and picked clean, then left 

 to dry on a clean surface. 



Preserving anatomical preparations Many specimens 



