22 M. Thouin on the Use of the Scoria, fyc. [Appendix. 



necessary in managing it were saved, and the dirt it occasions in 

 its removal avoided. 



It is scarcely necessary to observe, that the Scoria cannot 

 supersede the use of those tan beds where bottom heat is required 

 for the germination of seeds, for accelerating the growth of bulbs, 

 striking cuttings, or encouraging the growth of young tropical 

 plants : without bottom heat these objects of the horticulturist's 

 care would perish. 



