ADDITIONAL PRESERVATIVE FORMULA. 229 



saucers, oil of bircli, flowers of sulpliur, liellebore, pepper, 

 tobacco, are said to be "bogies," the last especially, to the 

 Dermestes beetles and their cousin, Anthrenus museorum. Try 

 them, but don't rely too much upon them, is my advice ; nor, 

 indeed, upon anything — not excepting even corrosive sublimate. 

 Trust only to exposure to light and constant supervision, zinc 

 or wii'e drying cases, and to " casing up " as soon as possible. If 

 sending specimens long distances, it is well to pepper the shot 

 parts, enclosing also in the parcel some pieces of charcoal 

 wi-apped in paper. Of course, if the specimens are not for the 

 table, dilute glacial carbolic acid, poured on the wounds and 

 down the throat, is the best thing to do, but it should always 

 be noted in an accompanying letter, for fear of accidents. 

 Smearing the hands and face with paraffin is said to keep 

 forest flies and midges- from biting. 



Preservation of Animal Tissue (see pp. 78-85). 



Chloride of zinc, 1 part. | Water, 20 parts. 



This formula appears to be one of the non-alcoholic preser- 

 vatives most suited for fishes in preparation jars. I have so 

 lately tried it that I cannot at present state if it is the very best. 



Picric Acid, formed by a certain chemical fusion of 

 carbolic acid with nitric acid, is recommended (when diluted) for 

 the preservation of soit-bodied animals, such as zoophytes, &c. 



Bichromate of Potash (see page 81), though so useful 

 for pickling fishes, moUusca, worms, and even " jelly fish " 

 and sea-anemones, is, I have found, liable to be attacked by 

 mildew; to prevent this add a few drops of phenic* (carbolic 

 acid). This salt is also used in microscopy to assist in fixing 

 glass covers on glass slides. The cement in question appears 

 so admirably adapted to many purposes, that I think it worth 

 quoting (see Science Gossip, 1879, p. 136) : 



Cox's gelatine, 2oz. | Acetic acid, fluid, 1 drachm. 



Gum ammoniac, 10 grains. 



" Dissolve in a water bath, and filter through cotton while 



warm. This cement remains fluid when cold, and dries quickly. 



After the ring has become set, or stiff, the whole slide is 



immersed for a minute or so in a 10-grain solution of bichro- 



* Phenol, Phenic Acid, Phenic Alcohol, Hydrate of Phenyl (CoH5HO]= Carbolic acid. 



