HARD WICKE ' S S CIENCE- G O SSI P. 



33 



during the various changes of its level, while Miller 

 detected in them the signs of a power now foreign to 

 this country. When Miller worked here, the boulder 

 clay was not so well exposed as it is now, and the 

 examination is thus rendered much easier. Owing 

 to the increase of trade at Leith, a new and very 

 large dock is being constructed to the east of the 

 town. In order to get a sufficient depth of water 

 the sea bottom has been excavated, and this has laid 

 open fine sections of the various deposits which have 

 accumulated there. 



The boulders are generally of greenstone ; and 



be made by one, who attempts for the first time, to 

 track the knowledge of early botanists on any point, 

 without some general knowledge of the subject- 

 matter, i.e., of the plants themselves. I propose 

 making the British forms of Thalictrum the most 

 prominent subject of my present investigation. 



British botanists are looking forward with interest 

 to the Guide to the Literature of Botany promised by 

 the Index Society from the pen of Mr. B. Daydon 

 Jackson, the accomplished editor of Turner's " Libel - 

 lus" and Gerard's " Catalogus ;" but, pending any 

 better arrangement, I venture to divide the history of 



Fig. 32. — Section showing the boulder clay, &c. near Leith. a, surface soil ; b, old sea-bed, with gravel layers ; c, boulder - 



clay ; d, present sea-bed. 



seem to have been carried from Arthur's Seat and the 

 Corstorphine hill, some distance inland. So far I 

 have not observed any of the west country rocks en- 

 closed in the clay ; but do not doubt that this is the 

 track of the great glacier which, according to Geikie, 

 had its origin away in the western highlands. 



Since the deposition of the boulder-clay in this 

 locality, the relative position of sea and land seems 

 to have changed twice. The following diagram 

 shows this ; and also gives a general idea of the posi- 

 tion of the deposit at Leith. On the top of the clay 

 is found a thick layer of sand and pebbles, giving un- 

 mistakable proofs of marine origin, by the stratified 

 order of the latter ; while the boulder clay is once 

 more raised above the bed of the ocean. A few 

 hundred yards from the beach, the boulder clay dis- 

 appears on account of the slight incline it takes 

 towards the sea, and unless this is noticed, the sudden 

 freeness of the shore from boulders is apt to confuse 

 the geologist. 



Robert Humphrey. 



THE CRITICAL BOTANIST. 

 [The History of Botany.] 



THE experience of recent years has clearly shown 

 the great value' of a historical or chronological 

 method of research in nearly every branch of science. 

 It may be well, therefore, in taking my own study of 

 the genus Thalictrum as an example of critical method 

 to give in considerable detail the materials as I have 

 collected them. Every study must have a beginning, 

 but many errors of interpretation will undoubtedly 



British botany into four periods, the first terminating 

 at the year 1670, the second at about the year 1746, 

 the third at 1829. 



Without going back to Solomon, or even to Aris- 

 totle and his pupil Theophrastus, who, born B.C. 371, 

 described some 500 plants, classified as trees, herbs, 

 and shrubs, I must 'just mention the name of Peda- 

 nius Dioscorides of Anazarba, in Cilicia, whose 

 Greek work on Materia Medica is believed to have 

 been written in the second century. It seems, how- 

 ever, to have been one of Pliny's main sources of in- 

 formation, and the author of the " Historia Naturalis," 

 born A.D. 23, died in A.D. 79. After the time of 

 Pliny it may truly be said, in the words of M. Crepin's 

 excellent " Guide du Botaniste en Belgique " — a work 

 well meriting an English imitation — "Avantle xvi e 

 siecle, la botanique ne peut etre considered comme 

 une veritable science. Elle n'etait que l'humble auxi- 

 liaire de la medecine ; les plantes n'etaient pas 

 etudiees pour elles-memes et les traites qui les 

 concernaient n'etaient, pour la plupart, que des com- 

 mentaires des ouvrages de Theophraste, de Dioscoride 

 et de Pline." Though in the sixteenth century the 

 Dutch may fairly claim the credit of possessing the most 

 illustrious names in botanical science, Fusch, Dodoens, 

 and L'Obel, we in England have reason to be proud 

 of the early date (1538) of the first botanical work 

 of "the father of British botany," William Turner. 

 Turner was born probably between 15 10 and 15 15 ; 

 his first work was entitled " Libellus de re Herbaria 

 Novus," and has been reproduced in facsimile, and 

 edited by Mr. Jackson ; his " Herbal " was completed 

 in 1 568, the year of his death. Remade Fusch, born 

 at Limbourg, about 1500, died at Liege in 1587, his 



