. 163 



this purpose they must be dried as quickly as possible. 

 The drying papers should be changed at least once a day for the 

 first few days and the following note may well be borne in mind : 

 " Two or tlyee changes of the driers during the first 24 hours 

 will accomplish more than a dozen changes after the lapse of 

 several days. The most perfect preservation of the beautiful 

 colours of some orchids has been effected by heating the driers 

 and changing them every two hours during the first day."* 

 In order to hasten the drying of succulent plants they should 

 be dipped (with the exception of the flowers) in boiling water, 

 and this is also a good plan to adopt in the case of those 

 specimens which are apt to lose their leaves in drying. To 

 reduce the thickness of some specimens, such as hard fruits and 

 so on, they may be thinned by cutting away the underside, 

 care being taken to see that the original shape can be made 

 out. 



142. The specimens when com- Preservation 



pletely dried should be mounted, and this is perhaps best done of Speci- 

 by sewing them on to the sheets with a needle and thread, never m 

 more than one species being fastened to the same sheet. 

 Fragile specimens must, be glued to the sheets, care being 

 taken not to use more glue than necessary, especially on the 

 flowers. Before being placed in the herbarium all speci- 

 mens should be poisoned to protect them from mould, 

 insects and vermin. Corrosive sublimate (bichloride of mercury) 

 is the poison usually employed which should be dissolved in 

 spirits of wine in the proportion of about \ oz. of the poison to 

 one pint of spirit. This should be applied to the specimens with 

 a large soft brush. The solution should not be allowed to come 

 in contact with metal or discoloration may result. Leaves and 

 other parts of the specimens which become detached should be 

 placed in small envelopes, the latter then being fastened to the 

 mounted sheets. At the foot of each mounted sheet should be 

 carefully noted the natural order, scientific and vernacular 

 name of the plant, locality where found, date of finding, name 

 of collector and details of useful characters not exhibited by 

 the specimen itself, such as colour of the fresh flowers, habit oi 

 the plant, and so on. All the sheets of the species belonging to 

 one and the same genus should be placed in one folded sheet of 

 strong paper, on the outside of which should be written the 

 natural order, the generic name and the names of the contained 

 species. A collection of dried specimens is termed a herbarium Herbarium, 

 and should be stored in cabinets, or small almirahs, provided 



*Asa Gray's Botanical Text Book, Volume I, page 377. 



M2- 



