r 297 



of hardv annuals. Close and persistent attention has been given 

 to the improvement of this flower, by raisers and others, for some 

 years past, and the result of this ungrudging devotion of its enthus- 

 iastic admirers is to be seen to-day in numerous beautiful plants, 

 bearing a wonderful display of most charming blossoms. 



The Sweet Pea has now such numerous devotees, many of whom 

 have but a faint notion of the possibilities of the flower, that this 

 would appear to be a sufficient justification for the publication of 

 this treatise. 



Cultural directions from a comprehensive point of view receive 

 very full consideration and the claims of the Sweet Pea for varied 

 purposes are dealt with in detail, etc. 



The book contains a chapter about the pests and diseases of 

 the Sweet Pea, and also some beautiful photographs. Finally the 

 author gives a complete list of Sweet Pea books. 



Artificial Aids to Forcing. The Gardener's Chronicle, no 3623, 

 p. 368, London, June 4, 1910. 



The principal means used for forcing plants artificially are 

 etherisation, subjection to low temperature, and treatment with hot 

 water. According to a report by Mr Charles Chevalier, of the 

 Brussels International Exhibition, the chief merits of etherisation 

 are that plants thus treated flower two months earlier than is 

 otherwise possible. As to the actual effect produced by ether our 

 knowledge in still incomplete. The prevalent opinion, however, is 

 that it causes a loss of water from the tissues and thus acts by 

 drying the plant. If etherisation is to be practised with success 

 it must be applied early, for example during October or November. 



The most important points to bear in mind in the application 

 of ether are that the temperature must not be too low (about 

 3 o_32 F.) and that the plants must be exposed for a fairly long 

 time to the action of the vapour. In the table given by Mr Che- 

 valier 72 hours is cited as a fair time if the preceeding season 

 has been wet, and 60 hours if it has been dry. It may be that 

 certain failures which have been reported in England are traceable 

 to the exposure having been of too short duration. Other anaes- 

 thetics which have proved serviceable substitutes for ether are 

 chloroform and carbon tetrachloride. 



The origin of the use of artificially obtained low temperatures 

 is due to the initiative of the cultivators of cut flowers at Aalsmeer 

 (Holland). M. P. de Vries, in his report on the " Influence of ar- 



