MODE OF DEYING PLANTS. 799 



which contaiDed them being perfectly dry and bibulous.* Henslow 

 recommends that, with the view of ventilating plants during drying, 

 holes should be made in the ordinary boards at regular intervals, and 

 that two of the inner boards should always be placed together, sepa- 

 rated by flat cross-bars, which may either be fastened to the boards 

 by liquid glue prepared from shell lac, or may be kept loose, and in- 

 serted when required. A complicated apparatus is suggested by M. 

 Gannal, the particulars of which are given in the Botanical Cfazette, 

 ii. 55 ; and there also another mode of drying is described, in which 

 plants, after having been kept in a press for a few hours, are exposed to 

 the sun, or placed on a stove or in an oven, in an apparatus called the 

 Coquette. This consists of two open covers made of strong iron-wire 

 network fastened into frames made of light iron rod, pressure being 

 applied by straps or ropes, as already mentioned. The open frames 

 allow the moisture to escape freely. Sheets of tin may be employed 

 to separate the different layers of plants in process of drying, so as to 

 hinder the humidity of one from reaching the other, or the inequalities 

 of the larger from injuring the smaller and more delicate. In the case 

 of plants with strong stems, they must either be split, or a sandbag, 

 of the same size as the boards, used so as to equalise the pressure. 



Peocess of Drying. — The plants when collected are to be placed 

 on the drying paper. In doing this a parcel of not less than four sheets 

 is put on one of the outside boards ; then the specimens are laid out 

 oarefuUy, preserving as far as possible their natural habits, and laying 

 out the leaves and other parts. Another parcel of drying paper is then 

 placed above these, and the same process is repeated with other speci- 

 mens until twelve such parcels have been placed together. Then one 

 •of the inner boards is laid down, and other layers of paper and speci- 

 mens are applied, untU the whole parcel is of sufficient size to be 

 subjected to pressure. After twelve hours' pressure, in most instances, 

 the paper is changed, the moist paper being hung up to dry ; and in 

 ■ transferring the specimens from the wet to the dry paper, a' large pair 

 of surgeon's forceps is used. The interval elapsing between the 

 changing of the paper may.]be increased or diminished according to the 

 nature of the plants and the state of the weather. In the course of 

 ■eight or ten days, ordinary specimens will be so dry as to require only 

 very slight pressure, with a moderate circulation of air. Some very 

 •dry plants, as, grasses, may require only one changing. Succulent 

 plants, such as Sedum and Sempervivum, continue to grow, however 

 much submitted to pressure, and the ordinary methods of desiccation 

 Already indicated. In order to dry these plants completely and rapidly, 

 it is necessary to kiQ them, by immersion in boiling water for five or ten 

 minutes — some recommend the use of a solution of arsenic as a means of 



"* See a description and drawing of this apparatus in Botanical Gaeette, ii. 69. See also 

 •drawing of drying apparatus in Gardeners' Chronkle, 1861, p. 76. 



