390 PE0CEEDING8 OF UNITED STATES NATIONAL MUSEUM. 



Pure powdered carmiue, a little chrome yellow, and liquor of ammonia 

 are the only substances necessary. The carmine is deposited on an 

 earthenware dish ; the ammonia is employed as water is by the water- 

 color painter, and traces of chrome yellow correct the tints which are 

 too purple. Finally, the white surface of the plate serves as a back- 

 ground on which the tints may be criticized. 



The muscles of the specimen are painted with the aid of an ammo- 

 niacal solution of carmine, taking the precaution not to cover the ten- 

 dons or bones, and in general those parts which should remain white. 

 In fact, these parts are protected by wrapi)ing them separately in strips 

 of tolerably thick paper. 



It is unnecessary for me to recall the fact that carmine tints the mus- 

 cles and penetrates them to a certain depth. 



This operation finished, it is next in order to fix the tint. For this 

 purpose the specimen is simply rejilaced in the bath of alum. An in- 

 soluble red laquer is formed, constituting two coats, the one superficial 

 and pulverulent (this comes from the bottom of the hquid), the other 

 penetrating much deeper into the muscular tissue itself and remaining 

 fixed in the tissue. 



From this time forth the carmine is fixed and the muscles are red, 

 having the appearance of fresh flesh, and may be handled for an in- 

 definite period without soiling the fingers of the operator with their 

 coloring matter. Specimens which we thus i^repared in 1872, have been 

 used every year in the comparative anatomy course, and have lost noth- 

 ing of their value. 



The next step is the employment of glycerine. The specimen is 

 plunged into a bath of phenolized glycerine, but, as the alum has al- 

 ready rendered the sj)ecimen proof against decomposition, a long macer- 

 ation is unnecessary, eight days being a sufiicient length of time. 



Finally, to place the specimen in a definite condition. It is well known 

 how annoying ordinary preparations are in which glycerine has been 

 used, it being necessary to let them drain for several months. Here we 

 have employed a more expeditious method. After having allowed the 

 specimen to drain for some hours, we wrap the members of the animal 

 and the trunk, in fact the entire body, in a covering of white filtering 

 paper, then in many coverings of ordinary gray paper, around the whole 

 of which twine is wound. 



One week after, the paper, which has absorbed all the glycerine in 

 excess, is taken off, the abdomen is filled with packing, the body is sewn 

 up, the muscles are restored to their proper position, and the specimen 

 is finished. 



Thanks, probably to the alum, the tendons are white and not yellow- 

 ish, as preparations are when made by ordinary processes. The muscles 

 are never found to be glued together. 



To state it briefly, the metliod is composed of the following opera- 



