78 MASSACHUSETTS HORTICULTURAL SOCIETY. 



jnirposes, due very largely to the extreme drouth of last summer, 

 ■we are no nearer a solution of the question than we were in 1905-'06. 

 We say " no nearer," in a qualified way; we do believe that we now 

 possess the key to the situation, and that the problem will be solved 

 whenever we can secure suitable plants upon which to continue 

 our experimental investigations. The problem before us is to find 

 a substitute for frost. 



CoiiPARATivE Efficacy of Various Anesthetic and Toxic 



Substances. 



Naturally the investigations upon rhubarb suggested a new line 

 of research into the comparative eflficacy of ether as compared with 

 other substances possessing anesthetic or toxic properties. This 

 line of work was undertaken during the winter of 1906-'07. The 

 substances employed were ether, chloroform, ethyl bromide, ethyl 

 chloride, ethyl iodide, methyl chloride, ethyl alcohol, and acetone. 

 The kinds of plants treated were lilacs, spireas, Aaburnums, prunus 

 pissardi, philadelphus, cydonia, asparagus, peonies, iris, dicentra, 

 lilies, lily-of-the-valley, hyacinths, tulips, narcissus, etc. The data 

 secured from the woody shrubs were not very satisfactory; a result 

 largely if not wholly due to an attempt to force field-grown plants, 

 stock which later experience showed could not have been success- 

 fully forced under any condition. However, sufficiently good results 

 were secured from some of the other plants, to indicate in a general 

 way at least that other substances could be substituted for ether and 

 chloroform in forcing plants into growth. 



Profiting by the previous season's experience the experimental 

 work of 19G7-'08 was confined very largely to pot-grown plants of 

 lilacs, azaleas, peonies, and iris. Work was also continued upon 

 bulbous plants and lily-of-the-valley. The results of the work with 

 lilacs were very satisfactory also that with astilbe. The azaleas 

 did not respond very noticeably to treatment except in cases where 

 too large a dosage or too prolonged a treatment was given, resulting 

 in the death of the plants. The data obtained from the treatment 

 of bulbous plants have not been sufficiently uniform to warrant any 

 coftclusions. In some cases a considerable growth acceleration 



