DOMESTIC GREENHOUSES. 91 



CHAPTER IX. 



entering on a description of this apparatus, the 

 circumstances under which it was discovered may be 

 briefly adverted to. Mr. Ward, the gentleman to whom 

 we are indebted for the discovery, is a surgeon, residing in Well- 

 close Square, London. From his earliest youth Mr. Ward has 

 been attached to botanical pursuits ; but living in a densely popu- 

 lated neighborhood, surrounded with manufactories, and enve- 

 loped in the smoke of London in its very worst form, he had been 

 compelled to give up the cultivation of plants, until the following 

 simple incident seemed to point out a mode by which he could 

 follow his favorite amusement with some degree of success. He 

 had buried the chrysalis of a sphinx in some moist mould, which 

 was inclosed in a glass bottle covered with a top. In watching 

 the bottle from day to day, he observed that when exposed to 

 the warmth of the sun the moisture rose from the mould, and 

 became condensed on the inner surface of the glass, and again 

 fell back upon the mould during the night, thus keeping up a 

 continual moisture in the atmosphere within the glass ; he also ob- 

 served about a week prior to the final change of the insect, a 

 seedling fern and grass appear on the surface of the mould. 

 Ifter having secured the insect, Mr. Ward set himself to observe 



* The materials for this paper mre chiefly from Chambers's Edinburgh 

 Journal, with some slight additions from Mr. Ellis's paper read to the Bo- 

 lanical Society of Edinburgh. 



