122 THE VICTORIAN KATURAUST, 



" blood heat" ( 1 00° F.), like that of mammals, and may be applied 

 artificially if the ordinary temperature is not sufficient, but in 

 this sunny climate of ours the natural heat is sufficient, taking- 

 the precaution, however, to guard against rain. 



(a.) Hot Sand Process. — The specimen is imbedded in the 

 sand, which has to be heated to the temperature of the human 

 body. The hot dry sand (silver sand being preferred) absorbs- 

 the moisture, and thus dries the specimen, while at the same time 

 there is sufficient pressure to prevent collapse and preserve the 

 shape. After the moisture has been driven out by the heat and 

 absorbed by the sand, the specimen is afterwards rendered 

 impervious to moisture by a coating of dammar varnish. This 

 may be prepared by dissolving gum dammar in kerosene,, 

 benzol, turpentine, or chloroform alone. Since turpentine 

 affects the colour of flowers, I prefer the solution in kerosene or 

 benzol. 



{b ) Patented Process. — In the patented process already 

 referred to, pigments are applied in the form of fine powder or 

 dust, corresponding to the natural colour, and flowers so treated 

 are afterwards dried in a bath of hot sand, when the colour is 

 fixed on their surface. This is hardly preserving the natural 

 colour, since an artificial colour is applied. 



(c.) Mr. English's JNlethod. — It is evident that other imbed- 

 ding material than sand may be tried — something which is 

 at the same time a good absorbent. Mr. English has used, 

 with excellent results, plaster of Paris, and he found that plaster 

 of Paris mixed with an equal quantity of lime did better still. 

 But there is this drawback to the latter method, that the lime 

 acts upon the colours, rendering reds rather purplish, which, 

 however, can be remedied by fuming with hydrochloric acid. 

 He says : — " I took ordinary plaster of Paris, warmed to about 

 go'* or 100* F., and imbedded the fresh flowers in it, shaking- 

 the plaster carefully down in the plants. This plan answered 

 admirably. Small plants were preserved in less than 1 2 hours ; 

 large species took longer in proportion to the amount of mois- 

 ture in their tissues. When taken out of the plaster these 

 plants presented a very dirty appearance, and if left in it too 

 long they became somewhat brittle, but on being laid aside in 

 the air for a time they soon relaxed. They were then brushed 

 with a camel's hair pencil, and petroleum carefully applied 

 with a brush. Reds and purplish-reds, however, come out too 

 purple. I overcame this difficulty at last by immersing the 

 dried plants in the vapour of hydrochloric acid. About a tea- 

 spoonful of acid is put into a wide-mouthed bottle or glass 

 cylinder, and the plants suspended by the stalks, so as not 

 actually to touch the liquid acid ; when the proper shade of 

 colour appears, they must be quickly removed." 



