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H. Goadhy on the Preservation of Animal Substances. §81 



When the B fluid is made according to the above recipe^ its 

 specific gravity at a temperature of 60^ will be 1-100, and with 

 it, terrestrial and fresh-wafer animals can be well preserved. 



For marine animals the strength of the fluid must be increased 

 by the addition of salt to M48, otherwise they will be decom- 



posed. 



stages 



the preserving process require alum, but it must be cautiously- 

 used, and carefully watched, and as soon as it has done all that 

 is required of it, the animal should be well washed in clean 

 water and placed in the B fluid. There is no objection to fre- 

 quent contact with alum, if necessary, provided the process be 

 conducted on the principle here laid down. 



The Arsenical Fluid, 



yft 



tng properties, I use it alone, unless the process is likely to oc- 

 cupy much time, and in that case, I combine it with the B fluid, 

 m the following proportions, and call it C: B fluid, as directed 

 above, arsenic 20 grains. Arsenic can no more be trusted with 

 carbonate of lime, than alum; and if it be desirable to employ 

 It on any molluscous animal the creature should be removed 

 from its shell prior to its introduction to arsenic. The solutions 

 of arsenic that I have employed differ in strength from 20 grains 

 to 60 grains to a pint of water, (imperial measure, 20 ounces) 

 or to the pint of B fluid. It is not easy to dissolve this mineral, 

 and the only plan which I have found successful, is to place 

 the quantity of arsenic to be dissolved in a Florence oil flask 

 with half a pint of water, apply a spirit lamp, and boil till the 

 whole be dissolved, it can then be diluted by the addition, either 

 of more water^ or preserving fluid. I may mention one singular 

 fact of preservation by this fluid, no less of the animal, than 

 (which is most important) its color 



^ Upwards of six years ago my son collected for me several spe- 

 cimens of the larvae of Cossus ligniperda, the peculiar color of 

 ^hich had never been preserved. In alcoholic fluid, of any 

 strength, it turns quite black, which is a common result of the 

 application of spirit for preserving caterpillars; in addition, most 

 insect colors are soluble in alcohol. 



The specimens included larvae of the first and second year, and 

 one fine sample of a three-year larva about to change to a chrys- 

 alis. Of the former specimens T preserved some in the A 2, and 

 the rest in the B fluid, and placed the last in a solution of arsenic. 

 The aluminous fluid has hardened and disfigured the caterpillars 

 nearly as much as spirit would have done ; they are softer, and in 

 a better state for dissecting, in tb^B fluid ; but they have lost all 

 their rosy redness of color in both fluids, and are partially black. 

 It was reserved for the arsenic to give me one caterpillar so 

 beautifully preserved that all its characteristic color, eyen to the 



Second Series, YoL XII, U"o. SG.— Noy^ 1851. - 49 . 



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