ON THE APPARATUS RELATING TO 

 VEGETABLE PHYSIOLOGY. 



EY SYDNEY H. VINES, B.A., B.SC. ; FELLOW OF CHRISTS 

 COLLEGE, CAMBRIDGE. 



IN describing and explaining to you the construction 

 and the use of the instruments relating to Vegetable 

 Physiology which have been contributed to the Loan 

 Exhibition, I will follow the order in which they are 

 arrang'ed in the Catalogue. 



The first object to which I would draw your attention 

 is this sketch (No. 3904 in Catalogue) exhibited by Dr. 

 Velten, Physiologist to the Institute for experiments 

 relating to Forestry in Vienna of an apparatus devised 

 for the investigation of the influence of temperature upon 

 living organisms. It consists of a box of zinc with 

 double walls, in the roof and sides of which panes of 

 glass are fixed, by means of which all that goes on within 

 can be observed, and in the sides are openings through which 

 the hands cased in india-rubber gloves, to prevent any 

 sudden change of temperature may be introduced into 

 the interior. The space between the walls is filled with 

 a liquid (water or oil), the temperature of which can be 

 raised by applying heat below, or lowered by placing a 

 refrigerator in the wooden case made to receive it. 



The use of this apparatus will, I think, be most clearly 

 demonstrated by a description of some experiments which 

 might be performed with it. In performing such experi- 

 ments we must be most careful to arrange that the 

 phenomena which we are to observe shall be dependent 

 only upon that one agent the action of which we are 

 investigating, namely, temperature. "We must therefore 



