86 
The President's Address. 
pal forms of plants found in Europe. The geography of plants 
found in him an able exponent,, and he constructed the maps 
and wrote the letterpress on the distribution of plants, in 
^ Johnston^s Physical Atlas/ He also further contributed 
to make this subject popularly understood, by translating 
from the German, Professor Schouw^s Earth, Plants, and 
Man/ His acquaintance with German botanical literature 
was extensive, and he translated into English Schleiden^s 
Lectures on the Biography of Plants,^ and Alexander 
Braun^s ' Rejuvenescence in Nature,' a somewhat specula- 
tive but interesting volume, published by the Bay Society. 
Although he had not the gift of free speech, his earnest 
desire to impart all he knew, rendered him a popular teacher 
in his class ; and when the late Professor Edward Eorbes 
resigned his chair at King's College, he was appointed Pro- 
fessor of Botany in his place. Besides being a member of 
our own Society, he was a Fellow of the Boyal and Linnean 
Societies, and had the appointment of Examiner in Natural 
Science at the Boyal Military Academy at Woolwich, and at 
the Society of Arts. He was of a retiring and amiable 
disposition, and sincerely beloved by all those who knew him 
in private life. He fought a brave fight, and is a bright 
example of what a firm will can do amidst the feebleness of 
habitual indisposition. 
In Mr. Andrew Boss the Society has lost one of its original 
members, and one who has had no little share in bringing 
the microscope to its present perfect state. He was an 
optician by profession, and laboured with Pritchard, Goring, 
Holland, and others, to bring the simple microscope to per- 
fection, before Mr. Lister had made his great discovery of a 
combination of achromatic glasses in a compound arrange- 
ment. Mr. Boss was one of the earliest makers who com- 
prehended Mr. Lister's principles, and carried them into 
practice in the manufacture of compound achromatic instru- 
ments. The perfect success, however, of these glasses was 
attended with a defect which in some measure was a draw- 
back to their usefulness. This arose from their use in the 
examination of objects covered with thin plates of talc or 
glass, as the corrections for uncovered objects were found erro- 
neous for those which were covered. Mr. Boss discovered the 
means of correcting this defect, which consisted in separating 
the anterior lens of the combination from the other two, in 
such a way that it could be brought further or nearer to 
them, according to the necessity of the case. An account of 
this discovery and its application will be found in the fifty- 
first volume of the Transaction of the Society of Arts,' pub- 
