FIXING AND PRESERVATIVE MEDIUMS 59 



sulphur is not to be thought of for one moment in museum 

 matters, as, when thoroughly done, it removes the colour from 

 nearly all natural objects. 



Such substances as camphor, tobacco, pepper, Russian 

 leather {i.e. leather dressed with oil of birch), Russian tallow, 

 fumes of turpentine or benzoline, and a dozen other " scents," 

 are of as much use as would be a label " Please don't touch." 

 Contact with a lethal fluid or substance is the only remedy, and 

 safeguarding all specimens by constant supervision the only 

 preventive. 



One substance, however, is certain in its effects, although 

 limited in application, and that is — 



Insect Powder. — This, which is, when genuine, made from 

 the flowers of the Russian tansy, is certainly a deterrent, if not 

 actually a lethal agent, and whether the smell attracts and 

 the fine dust smothers the insects, or whether it repels, or 

 whether it is really toxic in its effects, is very hard to discover. 

 Probably, however, it acts mechanically in some way, as dead 

 moths and other insects are frequently found around skins 

 it is protecting. There is no doubt that it is valuable, and 

 it should be kept in all drawers containing skins, and may, in 

 the case of delicately plumaged birds, be placed as a layer 

 underneath paper on which the skins rest. It is apparently 

 harmless, except to persons subject to " hay fever." 



Sprinkling inside a newly-made skin is the best method, but 

 when worked up in the preservative paste, or made as a wash 

 for the inside of skins, as follows, it is doubtfully efficacious. 



51. — Insecticide (M.B.) 



Insect powder (best) . . . . 4 oz. 



Hot water ..... i quart 



Bisulphide of Carbon (Riley, Directions for Collecting and 

 Preserving Insects, p. 1 10). — It is said, "If the collection is 



