

] 



U. Goadby on the Preservation of Animal Substances. 383 



creased, and intimately mixedj until the animal again rise, and in 

 time it will become saturated witl; this denser fluid. In many 

 instances it is advisable to. keep the animal forcibly at the bottom 

 of the vessel in which it is being preserved by weights^ and this 

 IS particularly necessary in hot weather when the preserving pro- 

 cess should be expedited with all the speed that is consistent 

 with safety. It is easy to ascertain if the animal be saturated 

 With the fluid by removing the weights, and in that case, to go on 

 ncreasing the strength pf the fluid: in fine, success depends on 

 carrying out the laws of endosmose, and exosmose. The diluted 

 fluid used in the first stages should be thrown away, and fre- 

 quently renewed, as, being replete with animal fluids, it contains 

 within itself the elements of decomposition, and increases the dif- 

 culty of obtaining ultimate success. This remark, however, ap- 

 plies less to the aluminous, than to the B fluid, as in the former, 

 the coloring matter, and animal deposits of all kinds so abundantly 

 seen when spirit is used and which occasions the steady and con- 

 stant discoloration of that fluid, for, in some cases, many years, 

 and which so generally tends to the disfigurement of preparations 

 in museums is altogether insoluble from the instant it, or they, 

 come, in contact with alum; and for this veiy important reason 

 alum may be almost always used in the early stage of preserva^ 

 tion, the former cautions on this subject being strictly attended 

 to. Preservation of animals by means of these fluids, then, can 

 only be accomplished by the daily addition of fluid until the 

 creature be saturated with the fluid of the full strength indicated. 

 Nor should the solicitude of the operator end immediately at this 

 point, as it will be necessary occasionally to renew the fluid an4 

 often to test its strength. To shorten this species of labor I long 

 ago procured a glass jar, or tube, two and a half inches long, and 

 three-fourths of an inch wide, with a flat bottom, to be used as a 

 P^oof glass ; I then adjusted some specific gravity bubbles so ac- 

 curately that they rise very slowly in the fluid, the precise strength 

 of which they are intended to indicate ; if the fluid be weaker 

 than exact strength, they fall to the bottom, and there remain ; if 

 stronger, they quickly rise. They are marked on the top A I, 

 -^^5 B, S, the latter indicating a saturated solution of rock salt 

 ^Uh which it is convenient to increase the daily strength of the 

 -o fluid in the manner already described. 



. 6y pouring a little fluid into the small proof glass, and apply- 

 *^g a bubble as the test of strength of the fluid that has been 

 employed^ the operator will instantly learn, not the exact strength, 

 (which is unnecessary,) but that tlie fluid is either oi the strength, 

 or weaker or stronger;— all the information he needs to guide 

 him in his labors. 



Instead of the bubble marked "B" I would substitute two, 

 one indicating 1-100, the other M48j and the Italian barometer 



J 



