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BULLETIN 67, UNITED STATES NATIONAL MUSEUM. 



cork is poor or the vial cracks, the specimens are soon dried and 

 may be ruined. To obviate this one can mix with the alcohol a 

 little glycerine, about 1 or 2 per cent, or even less. Then if the 

 alcohol evaporates the glycerine will keep the specimens moist for a 

 long while. Specimens that have been dried can often be softened 

 by soaking in warm water, and dipping in hot water, before putting 

 them back in alcohol. 



Other liquids. — Various other liquids have been tried as substitutes 

 for alcohol. Formalin is the best as far as results are concerned. 

 In fact, many larvse preserved in a mixture of 1 part commercial 

 formalin and 10 parts water (a 4 per cent solution), or even in a 

 weaker solution, will keep as well or even better than in alcohol. 

 The vapor from a dish of formalin will injure one's eyes, and when 

 on the fingers it hardens the skin, so that it is not popular with 

 those who wish to study their preserved material. For museum 

 purposes, where specimens are rarely examined, it may find a place. 

 It should be noted, however, that it will corrode zinc, and some 

 styles of jars have zinc tops. Glycerin tends to darken specimens, 

 so should not be used except in small quantities mixed with other 



Fig. 110.— The Marx tray for specimens in alcohol. 



liquids. Mr. Barber has tried various combinations of alcohol, 

 formalin, glycerin, and carbolic acid, but found none that would 

 preserve better than formalin. The mixture of alcohol and formalin 

 usually produces a black precipitate, while the addition of glycerin 

 darkened the specimens. A liquid known as synthol has been put 

 on the market, but has no advantages over alcohol, except perhaps 

 in price. 



Storing alcoholics. — There are many ways of storing vials of alco- 

 holic material. A cheap way is to take an empty cigar box and 

 divide it into small squares by cross strips of stiff paper or card- 

 board, on the style of egg boxes. An ordinary box will hold about 

 60 or 66 2-dram vials. A much better way is the use of slender 

 trays, often called Marx trays, as shown in the illustration (fig. 116). 

 This has a cork top with holes punched in it for the vials. A more 

 economical plan is to discard the cork top and make the tray wide 

 enough for two rows of vials (fig. 117). Then put a cardboard strip 

 down the middle, with side partitions for each vial. Where one does 

 not expect to examine specimens very often, the vials may be canned 



