to his Observations on the Optical System of Mineralogy. 203 
reader’s decision, whether I am not justified in the opinion I 
have expressed, that the connection between the optical charac- 
ters of* minerals and their crystalline forms, is not yet sufficient- 
ly understood. 
Art. XXI . — Some Account of the School of Arts of Edin- 
burgh. 
rgi 
_JL HE public have heard a great deal during the last year of 
institutions being established in different parts of the island, for 
the diffusion of scientific knowledge among operative mechanics, 
and several periodical publications in a cheap form, have of late 
appeared with the same laudable purpose. It is an important 
epoch in the history of the country, and a spirit has been 
awakened, which, if properly directed, may be productive of the 
most beneficial effects, not only by ameliorating the moral con- 
dition of a great mass of the people, but also by increasing 
the skill and prosperity of our various branches of manufacture. 
We are of opinion, therefore, that a brief account of the School 
of Arts of Edinburgh, which has now existed for three years, 
will be acceptable to our readers. 
It is to Dr Birkbeck that the merit is unquestionably due, of 
having first proposed a plan for conveying scientific instruction 
to mechanics. While he was resident in Glasgow, and held the 
situation of Lecturer in the Andersonian Institution, about the 
year 1801, he gave lectures on Chemistry and Natural Philoso- 
phy to operative mechanics on certain days set apart for that 
purpose, a plan which was followed up by his successors, and has 
been considerably extended and improved by Dr L T re, who now 
delivers the lectures in that establishment. The valuable sug- 
gestions which Dr Birkbeck had thrown out remained unheeded 
for twenty years; for we believe, that, during the whole of that 
time, the lectureship which he had founded, was the only thing 
of the sort that existed in the united kingdom. 
About the autumn of 1820, Mr Leonard Horner proposed the 
establishment of a school in Edinburgh, in which such branches 
of science as would be useful to mechanics in the exercise of their 
trade, might be taught at convenient hours, and at an expence 
