354 



The Scottish Naturalist. 



so preventing all interference with the specimens. The 

 choice of colour of the background is of some consequence, from 

 its effect in bringing the specimens more or less clearly into view. 

 In some museums light tints are preferred in lining the cases; 

 while in others dark tints (e.g., dark blue), are thought more suitable. 



A still more important matter is the complete exclusion of dust, 

 for which special provision should always be made. It cannot be 

 said, however, that complete success has yet been attained in this 

 direction. 



Equally necessary, and on the whole less difficult, is it to pre- 

 vent the destruction of specimens by the larvae of insects (moths, 

 &c), or by mites. The same means that are employed to exclude 

 dust will exclude these foes ; but they should be supplemented by 

 the use of camphor, or (better) of naphthaline, in the cases ; or by 

 fumigation of infested specimens with carbon-disulphide in a 

 closed vessel, or by treating them with solutions of corrosive 

 sublimate or of arsenious acid. Injury from mould is usually felt 

 only in damp museums, and may be prevented by the use of the 

 solution of corrosive sublimate, or of carbolic acid on cotton, and 

 by thorough drying. 



It is scarcely needful to say that the collections require to be 

 watched to prevent such injuries, and that specimens may require 

 to be cleansed from dust at times. 



In. commencing a museum it is wise to determine before-hand 

 what it shall contain, i.e., whether the collections shall be ex- 

 clusively archaeological, botanical, geological or zoological, or shall 

 include two or more of these groups, and also industrial and 

 technical collections. In Provincial Museums general experience 

 may be held to prove that there should be two aims in view, viz. : 



1. To form complete local collections in the group or groups of 

 subjects included in the museum. 



2. To form an Index-collection, selected for educational purposes 

 alone, which shall include representative specimens of the several 

 divisions or grades in each group, irrespective of locality. 



In the botanical and zoological museums the life-histories of 

 the species should be represented so far as can be done — a task 

 that imperatively demands very special qualifications in the 

 operator, with extensive experience both in the technicalities of 

 the work and in the field. Models and casts are often of very 

 great value in fulfilling both the above aims. 



