244 COSMOS. 



main of analytic chemistry. It is true that his hopes were 

 directed to the transmutation of the metals, but in his at- 

 tempts to fulfill this object he not only improved the practical 

 manipulation of ores, but he also enlarged the insight of men 

 into the general mode of action of the chemical forces of na- 

 ture. His works contain some extremely acute observations 

 on the organic structure and physiology of plants. He was 

 acquainted with the sleep of plants, the periodical opening 

 and closing of flowers, the diminution of the sap during evap- 

 oration from the surfaces of leaves, and with the influence 

 of the distribution of the vascular bundles on the indentations 

 of the leaves. He wrote commentaries on all the physical 

 works of the Stagirite, although in that on the history of ani- 

 mals he followed the Latin translation of Michael Scotus from 

 the Arabic* The work of Albertus Magnus, entitled Jjiber 

 Cosmographicus de Natura Locoinwi, is a kind of physical 

 geography. I have found in it observations, which greatly 

 excited my surprise, regarding the simultaneous dependence 

 of climate on latitude and elevation, and the effect of differ- 

 ent angles of incidence of the sun's rays in heating the earth's 

 surface. Albertus probably owes the praise conferred on him 

 by Dante less to himself than to his beloved pupil St. Thomas 

 Aquinas, who accompanied him from Cologne to Paris in 1245, 

 and returned with him to Germany in 1248. 



Questi, che m'e a destra piu vicino, 

 Frate e maestro fummi ; ed esso Alberto 

 E' di Cologna, ed io Thomas d' Aquino. 



Jl Paradiso, x., 97-99. 



In all that has directly operated on the extension of the 

 natural sciences, and on their establishment on a mathemat- 



* The greater share of merit in regard to the history of animals be- 

 longs to the Emperor Frederic II. We are indebted to him for import- 

 ant independent observations on the internal structure of birds. (See 

 Schneider, in Reliqua Librorum Frederici JL, imperatoris de arte venan- 

 di cum avibus, t. i., 1788, in the Preface.) Cuvier also calls this prince 

 of the Hohenstaufen line the " first independent and original zoologist 

 of the scholastic Middle Ages." On the correct view of Albert Mag- 

 nus, on the distribution of heat over the earth's surface under different 

 latitudes and at different seasons, see his Liber Cosmo graphicus de Na- 

 tura Locorum, Argent., 1515, fol. 14 b. and 23 a. (Examen Crit., t. i., 

 p. 54-58.) In his own observations, we, however, unhappily too often 

 find that Albertus Magnus shared in the uncritical spirit of his age. He 

 thinks he knows " that rye changes on a good soil into wheat ; that 

 from a beech wood which has been hewn down, a birch wood will 

 spring up from the decayed matter; and that from oak branches stuck 

 into the earth vines arise " (Compare, also, Ernst Meyer, ZZ-fier die Bo 

 tanik des 13ten Jahrhunderts, in the Linncea, bd. x., 1836, s. 719.) 



