60 SIR WILLIAM FLOWER CHAP. 



well understood, which had also stood the test of 

 time, three possibilities presented themselves. New 

 ideas might be evolved. New material might be 

 found, either to keep the preparations from decay 

 or to replace the glass vessels in which they were 

 contained. Lastly, a new and suggestive order of 

 arrangement and classification might be evolved. 

 The last was part of Flower's general scheme and 

 principle. For the first he was ready with a plan 

 for labelling every essential part of the objects in 

 the liquid in which they were suspended. The use 

 of new material was also to some extent practised, 

 and in very ingenious fashion, though it was found 

 that the old-fashioned spirits of wine were in the 

 main the most suitable medium for preservation. 

 The next object after securely preserving the speci- 

 mens was that the glass and the liquid containing 

 them should be absolutely colourless, like water. 

 When improved methods of glass-making rendered 

 it possible, flat-sided glass cases were used, and the 

 tops fastened on and hermetically sealed. Even in 

 this there were occasional difficulties. When india- 

 rubber, which formed part of the sealing solution, 

 became scarce and dear, an inferior preparation was 

 supplied by the trade, the use of which might have 

 endangered specimens designed to last for ever. 

 Consequently the Museum authorities began the 

 practice of purchasing- the ingredients for the sealing 

 substance themselves, and making it up in their 

 own laboratory. Labelling the different parts of 



