PRESERVATION OF MUSEUM SPECIMENS. 555 



Slice the soap, melt it, add the potash, stir in the arsenic, and add the 

 camphor previously dissolved in the alcohol. Stir, when cooling, to pre- 

 vent the arsenic from sinking to the bottom. For use, mix a small 

 quantity with water until it resembles buttermilk, and apply with a 

 common paint-brush. This is a mechanical mixture. Mr. Hornaday 

 has obtained results of the highest order from its use. The following 

 is believed to be a more correct chemical combination : 



White soap = 1 ounce. 



Arseniate of potasli 2 do. 



Water 6 drachms. 



Camphor 2 do. 



Strychnine (ad lib. ) 15 grains. 



The following ingredients make an effective preservative powder : 



White arsenic „ 1 pound. 



Burnt alum 1 do. 



Powdered oak bark 2 do. 



Camphor f do. 



This should be powdered well, sifted and kept in well- stoppered bot- 

 tles. It should be applied to the wet surface of skin and rubbed in 

 well. The hands should be protected with gloves. I have never tried 

 this preparation. 



The following solution has been prepared by Wickersheimer for the 

 preservation of objects in the natural state : 



Alum 500 grains. 



Salt 125 do. 



Saltpeter 60 do. 



Potash 300 do. 



Arsenic trioxide (white arsenic) 100 do. 



Dissolve in 1 quart of boiling water. Cool and filter, and for 1 quart 

 of the solution add 4 quarts of glycerine and 1 quart of alcohol. Either 

 soak the objects in the solution, or inject them with it. This solution is 

 said to do very well except in tropical climates. 



For botanical specimens this is said to be an excellent preservative : 



One ounce of corrosive sublimate to 1 quart of alcohol, diluted 50 

 per cent. The best plan is to dip the specimens and then carefully dry 

 them. The poison can also be painted on with a camel's-hair brush. 



For the preservation of entomological specimens, the strongest solu- 

 tion used should be corrosive sublimate in alcohol, 1 to 100, and the 

 weakest 0.1 to 100. (See remarks on naphthaline, ante.) 



For insects on plants, the following solutions are recommended : 



First solution. 



Salt 2-J pounds. 



Saltpeter 4 ounces. 



Water 1 gallon. 



Filter. 



Second solution. 



First solution 1 quart. 



Arseniate of potash 2 ounces. 



Water 1 gallon. 



