THE REPRODUCTION OF FISHES FROM WAX MOULDS 243 



Gutta-Percha Moulds 



The gutta-percha and wax composition (Formula 76, p. 85), 

 melted in a water-bath, does very nicely to pour over objects 

 such as small fishes, as it sets so rapidly as not to burn them, 

 and gives wonderfully sharp detail ; it is, however, subject to 

 the same drawback as the moulds made entirely of wax (see 

 following), that, unless poured over in one unbroken layer, it 

 shows lines of junction. Both this and the following, if thin, 

 should be backed with a " jacket " of plaster. 



Ordinary Wax Moulds 



Beeswax or Japan wax moulds have certain advantages 

 over the glue moulds, in being impervious to wet or damp, 

 and so may be used for fishes and such objects. They are, 

 however, subject to "blows," and, unless for small things,, or 

 unless done very quickly, show wavy lines where the wax 

 flows but does not unite with another rapidly-cooling edge. 

 All waxes for casting must give place to the following, which 

 is, at present, probably used for such purposes only in the 

 Leicester Museum. 



Paraffin Wax Moulds 



Paraffin wax, which is quite as cheap as the unmixed Japan 

 wax, unlike it, does not answer as a modelling-composition, hav- 

 ing no tenacity. It will occasionally serve for making a model 

 of a small specimen, but its chief and most valuable use — in 

 this far excelling any other wax, or, indeed, any other material 

 — is that to which it is now applied in the Leicester Museum, 

 namely, the casting of such objects as fishes, etc., or groups of 

 fishes, for reproduction in plaster. For this it is unrivalled, as, 

 although setting directly upon a cool surface, it liquefies imme- 

 diately, and unites without the slightest blemish upon more 



