THE LIBkAR^. 77 



study Applied Botany written more in the severe style 

 of the scientist in dealing with the data and scientific 

 deductions of inductive science, than in that which befits 

 the expression of emotions called forth by the contempla- 

 tion of discerned truth, is one entitled Causas dela Ascension 

 de la Savia, or sap, based on the able works of Dr Boehm. 



Another paper by Senor Alvarez which I may cite in 

 illustration of the character of the studies in research 

 pursued in this department of forest science in the School of 

 Forestry in the Escurial, and of the kind of publications to 

 which students may have access in the prosecution of 

 their studies, is one entitled Temperatur del Arbyr, Tem- 

 perature of the tree. The following translations of 

 excerpts from this will, I think, better indicate the 

 character of it than would any summary I could give of its 

 contents. In introducing his subject the author writes : 



' Amongst the repeated experiments which have been 

 made on the temperature of trees, those made by Boehm 

 and Breitenlohner, which we are about to bring under 

 consideration, deserve special attention.* 



' Krutzsch, professor in the Forest Institute of Tharand, 

 published observations made by him during the years 

 1852 and 1853,t and Becquerel has published in a series 

 of dissertations his experience, the principal object of 

 which was to determine the thermometric or climatic 

 influence of the forest.}: In the meteorologico-forestal 

 observations of Bavaria and Switzerland, the internal 

 temperature of trees has also been the subject of observa- 

 tion ; but up to this time there has only been published 

 a resume of the data obtained during the first years. 



' From these and other experiments, it appears that the 

 periodical and irregular changes of temperature influence 

 differently different parts of the tree, from the roots to the 

 branches. The atmosphere and the soil are two factors 



* V. Band LXX. Der Sitz. der K. Akad. d. Wissensch., I. Abth. Mai Heft. 



t Untersuchunyen ueber die Temper atur der Bauine, etc., 1854. 



{ Memoires de L'Acadeniie des Sciences, 1861-64. 



ZeUachrtft, der Outer reicliiiictien GeselLacha/t/aet- Meteoroloyie, Baud IV. 



