1362 BULLETIN OF THE BUREAU OF FISHERIES. 



first be immersed in water slightly warmer than the temperature mentioned. 

 In no circumstances attempt to brush the wax on, but fill the brush and dab it 

 on with one stroke of the end of the bristles, repeating until the surface is well 

 coated, when the cloth and wire may be added as above described. 



II. PLASTER CASTS FROM GLUE MOLDS. 



When plaster casts are desired, the mold is prepared and treated as in wax 

 casting, except that the warm-water bath may be omitted. With a soft 

 brush work the thinly mixed plaster into every part of the mold until a coat 

 has been applied to the entire surface. 



While this coating is in a semisoft condition, dip white mosquito netting 

 into thin plaster and lay on one or two thicknesses to increase the strength of 

 the cast. The addition of burlap treated in the same manner will greatly assist 

 in reducing the weight of such specimens. During warm weather it is advisable 

 to inject and wash the specimen with formalin before posing, to prevent the 

 quick decomposition likely to follow the application of the warm glue. As a 

 further precaution the cooling process may be hastened by artificial means. 



III. FISHES IN COPPER. FROM WAX MOLDS BY ELECTROPLATING PROCESS. 



The most difficult part of the work of preparing fishes is the reproduction 

 of their silver and iridescent colors. Metal "leaf" and washes produce but a 

 slight resemblance to the original, and the resultant loss of detail and final dis- 

 coloration of parts so treated emphasizes the necessity of preparing the highly 

 metallic colored specimens in a manner whereby these difficulties may be 

 avoided. 



Some of the iridescent tints are imitated by the use of prismatic colors, but 

 a white silver, or the various shades of this metal, as seen in the color of fishes, 

 are possible only through a solid silver base. 



Leaf and metal washes are not only dull in color, but are greatly darkened 

 through the refraction of light, and it is impossible to secure brilliant effects by 

 their use. The below-described method overcomes these difficulties, and such 

 specimens are not only accurate of form and detail, but are durable. 



The fish is posed as for glue molds, except the clay dam and coating of oil, 

 which are omitted. The proportion of two pounds of paraffin to two pounds 

 of bleached beeswax is melted in the double boiler and one tablespoonful of 

 Canada balsam added to that quantity. Best results in flowing the wax are 

 obtained by beginning at the tail with sufficient wax in a dipper (or other easily 

 handled vessel) to insure a speedy and complete covering of the entire specimen. 

 Allow the excess of wax to flow off and repeat several times at intervals, when a 

 layer of absorbent cotton is spread on and saturated with the wax. In this 



