442 MANUAL OF THE MOLLUSCA. 



shell-fish, inteudecl for the examination of their lingual teeth ; for if put up 

 iu strong spirit they become so hard that it is almost impossible to make 

 good preparations from them, and in weak spirit they will not keep for any 

 length of time. ' 



Alcohol. — The cheapest alcohol for preserving natural history objects, at 

 home, is sold as " methylated spirit ;" it contains ten per cent, of ordinary ! 

 wood spirit, and being undrinkable, is free of duty. When many specimens 

 are put up together the spirit becomes much diluted, and should be changed. 

 The soft tissues of bivalves, and spiral bodies of the univalves soon decompose 

 in weak spirit. But for permanent use, in Museums, proof spirit may be 

 diluted with an equal bulk of water. Cotton wool may be put with the spe- 

 cimens in spirit, especially with cuttle-fish, to preserve them from distortion 

 by pressure. 



Goadbys solution is prepared by dissolving \ lb. of bay salt, 20 grains of \ 

 arsenious acid, or white oxide of arsenic, and 2 grains of corrosive sublimate, 

 in 1 quart of boiling rain-water. 



Burnet's solution (chloride of zinc), largely diluted, is now used at the 

 British Museum for the preservation of fishes and other objects, iu glass jars, j 

 It has several advantages over spirit ; being undrinkable, and not inflammable, j 

 and the concentrated solution (sold by all druggists) is much less bulky. \ 



Muriate of Amraonia is recommeuded,by Mr. Gaskoin, for removing any f 

 unpleasant odours which may arise f/om preparations when taken out of J 

 spirit for examination. (See p. 430.) 



A solution of Chloride of Calcium has been employed by Gen. Totten, j 

 U.S. Engineers, for preserving the flexibility of the epidermis in various shells. \ 

 The solution of this deliquescent salt (which any one can make by saturating l 

 hydrochloric acid with marble), keeps the object which has been steeped in it I 

 permanently moist, without injuring its colour or texture ; while its antiseptic » 

 properties will aid in the preservation of matters liable to decay. (Prof, j 

 J. W. Bailey, iu Silliman's Journal, July, 1854.) 



Aquaria. \ 



The establishment of fresh-water and marine aquaria by Mr. Mitchell, in j 

 the gardens of the Zoological Society, and the writings of Mr. Philip Gosse, j 

 have popularized the subject of aquatic animals, and shewn how easy and j 

 interesting it is to keep a few of them alive, and watch their habits even in | 

 the midst of London. Instead of the solitary gold-fish in its globe of glass, ; 

 we may now have a variety of fishes in a little world of aquatic plants and ,, 

 water-insects and fresh-water shells. Salt-water may be brought from the 

 sea, or manufactured at home ; and a glass jar or tank of any size, may be : 

 tenanted with small sea-fish and soldier-crabs, sea-anemones, shrimps, and j 

 periwinkles.* )! 



* All the materials for fresh--water and marine aquaria, including live plants and 

 lishes, may be obtained of W. A. Lloyd, 164, St. John Street Road, London. 



