H. BOTANY AND HORTICULTURE. 293 



cernecl, is to see that the carbolic acid is entirely eliminated. 

 In one. experiment a discharge of gas was allowed to take 

 place for three hours daily for a period of an entire year, and 

 the effect, if any thing, was to secure a fuller development of 

 the plant. 



All that those experiments appear to prove, however, is 

 that perfectly pure illuminating gas is not injurious to the 

 roots of vegetation, the fact remaining demonstrable that or- 

 dinary gas does have a marked noxious effect. The elaborate 

 communication in 1858 to the Philadelphia Academy of Nat- 

 ural Sciences, by Mr. Fahnestock, shows this very clearly in 

 a case where the contents of a large green-house were de- 

 stroyed. In another instance, a stroke of lightning, passing 

 alono: the street ffas-mains in Racine in 1867, disturbed their 

 joints and caused a leakage which resulted in the death of 

 nearly all the shade-trees along an entire square. 15 (7, 

 1870, 86. 



DRYING FLOWERS, ETC. 



A method in use on the Continent of Europe for drying 

 herbs, flowers, etc., and keeping them in drawers free from 

 moisture, especially in damp weather, may be applied not in- 

 appropriately to the preservation of certain objects of natural 

 history, especially prepared plants and insects. This plan 

 consists in inserting a shallow tin pan in the bottom of the 

 drawer, and fitting to it a covering of metallic gauze or mus- 

 lin. Fused carbonate of potash is to be placed in the pan, 

 and the objects are allowed to rest on its porous cover. Rose- 

 leaves and other delicate substances may be dried in this 

 way without losing any of their perfume. Where the mate- 

 rial to be dried contains much water, it is necessary to change 

 the carbonate of potash occasionally, and to remelt it. In ad- 

 dition to the apparatus mentioned, the drawer should have a 

 tightly-fitting lid on top, so as to close it more completely. 

 14^4,1870,358. 



PREPARATION OF WOODEN LABELS FOR PLANTS. 



Wooden labels for plants, to.be inserted in the ground, 

 may, it is said, be preserved for an indefinite time by first 

 dipping them in a solution of one part of copper vitriol 

 and twenty-four parts of water, and subsequently immersing 



