LINNEAN SOCIETY OE LONDON. XXVll 



" In 1821, at tlie early age of 23, he appeared as an author, com- 

 municating to the Geological Society his ' Supplementary Observa- 

 tions on Dr. Berger's Account of the Isle of Man,' containing a 

 map and sections, to the preparation of which he had devoted his 

 spare time whilst spending two long vacations on that island with 

 pupils. At about that period the same duties also led him to the 

 Isle of Anglesea, the geology of which he diligently explored, and 

 embodied the results in a most elaborate paper, pi'inted in the 

 first volume of the ' Cambridge Philosophical Transactions.' This 

 paper not only at once raised its author to a very high position, 

 and caused such a demand for the volume in question that it was 

 soon out of print ; but it is to this day quoted by geologists as a 

 model of truthful and sagacious scientific research. It possesses 

 also rare merit, as combining with great power of co-ordinating 

 physical features, skill and accuracy in the application of chemistry, 

 mineralogy, mathematics and drawing to the illustration of a very 

 complicated mountainous region. 



" At this period, too, his physical powers were equal to his mental ; 

 and during his geological excursion in Anglesea he once walked 40 

 miles in the day, with his hammer and specimens on his back, 

 and danced all the following night at a ball ! 



" About the same year Professor Henslow took up botany with 

 the same zeal and method which he had devoted to other branches 

 of science, being, it is believed, first attracted to morphology and 

 physiology. He soon, however, found that no satisfactory know- 

 ledge of these branches could be acquired without a previous ac- 

 quaintance with systematic botany ; and this, joined to his ardour 

 for collecting, led him to the formation of a herbarium, in which 

 he displayed not only the specimens, but the structure of their 

 organs, their relations, variations, and aberrations. In 1822 the 

 Professorship of Mineralogy becoming vacant, he became the suc- 

 cessfid candidate ; he held the appointment for three years, con- 

 scientiously devoting the whole of his time to the study, and 

 especially to the chemical and crystallographical branches of it, 

 for which his mathematical powers and previous training eminently 

 qualified him. He prepared and published an admirable syllabus 

 of his course of lectures, followed by a systematic list and analy- 

 tical tables, drawn up with the same scientific precision and clear- 

 ness that characterize all his labours. 



" In 1825 the Professorship of Botany became vacant by the 

 death of Professor Martyn, and for this Professor Henslow re- 

 signed the miueralogical chair ; applying all his energies and ma- 



