15 
of Edinburgh , Session 1872 - 73 . 
in throwing off this enemy, he subsequently suffered from pleurisy, 
and also from liver complaints. Again restored to health for some 
time, he was seized, in May 1871, with obstinate giddiness, which, 
although it disappeared and left him apparently well, was never- 
theless the presage of his end ; for, on the 1st of April last, he was 
found dead in bed, having to all appearance sustained an attack of 
apoplexy during the night. He died in the 67th year of his age. 
Mohl published his researches chiefly in the form of occasional 
papers or monographs. He is the author of two books only, the 
one on Micrography, the other on The Vegetable Cell. But his 
occasional papers are no fewer than ninety in number, the most 
remarkable of which belong to the domain of Vegetable Histology 
— the earliest and most important being his treatise De Palmarum 
Structura, published in 1832, in his twenty-sixth year. Many of 
his writings relate also to Vegetable Morphology and Botanical 
Geography, and some to Botanical Physiology. In every branch 
his researches display much originality, and have added materially 
to the structure of modern botanical science. 
Professor von Mohl was a tall, strong man, a bachelor, reserved 
in manner and disposition, of retired and somewhat peculiar 
habits, in all things conscientious and upright, free altogether 
from vanity, regardless of all consequences in upholding the 
truth, entirely devoted to scientific research. 
Having now discharged to the best of my ability, within the 
space to which I am confined by the necessary limits of this 
address, the duty owing to the memory of our Fellows who have 
been removed from among us by death during the twelvemonths 
just concluded, I do not know that I can apply the rest of your 
time this evening better than by referring to the present position of 
certain scientific proceedings in which the Society takes an interest. 
The first subject I shall take the liberty of bringing under 
your notice is the present condition of the Ordnance Survey of 
Scotland. 
I am almost afraid to say — in the year 1872 — when the 
Government Survey of our division of the United Kingdom was 
commenced; hut it had made some progress when I witnessed a 
demonstration, by the chief surveying engineer, of the construe- 
