234 GOLDFISH VARIETIES AND 
permanent position is to melt by alcohol blow-torch some chips of gum 
shellac. This melting is done in the aquarium directly around the tube 
and is continued until a small mound is formed. A piece of wet cardboard 
will protect nearby glass from the heat. Gum shellac has perfect 
resistance to water. It will adhere to almost anything and is of especial 
value in connecting glass to metal. When cool it is quite hard. 
