THE LIBKAKV. 5l 



township ; the age of the plant ; the month in which it 

 was gathered ; the portion or part of the plant analysed ; 

 the colour produced by the salt of iron, and the tannin 

 contained in 100 parts of dry material ; and the results 

 of experiments on the influence of light. 



In the next chapter are discussed tannin plants, aud 

 causes determining the greater or less abundance of tannin, 

 under the headings of general ideas, flowers, fruits, leaves 

 and galls, barks, and determination of the times most favour- 

 able for the debarking of the trees in regard to the conserva- 

 tion and development of these; does the richness of the bark- 

 ings vary with the season in which the debarking occurs ? 

 the age at which the debarking should be executed, and the 

 methods of utilisation most convenient for the Casquizales j 

 the influence of heat, humidity, soil, and light on the pro- 

 duction of the tannin ; methods of disbarking trees. And the 

 chapter closes with a detailed account of the principal 

 lignous plants made use of in the tannin industries. 



SECTION 2. STUDIES OF THE SECOND YEAR. 



The studies of the second year embrace, as has been 

 stated, theory and application of Mechanics, Geodesy, 

 Meteorology and Climatology, Construction and Drawing. 



Sub-Section 1. Meteorology and Climatology. 



In Spain, as in other similarly situated countries in 

 which are included some of our colonies and dependencies 

 questions connected with meteorology and climate, and as 

 pertaining thereto, means of preventing disastrous conse- 

 quences from drought, torrents, and inundations, and of 

 securing an equitable diffusion in time and space, if not 

 also an increased rainfall, and humidity of soil and climate, 

 are of importance. 



In illustration to what students have thus been trained 

 to attempt and accomplish, I may refer to papers of 



