LINNEAN SOCIETY OF LONDON. XXvii 
“Tn 1821, at the 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, printed 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 ata 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- 
cessful 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 bis 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. 
“Tn 1825 the Professorship of Botany became vacant by the 
death of Professor Martyn, and for this Professor Henslow re- 
signed the mineralogical chair; applying all his energies and ma- 
