419 
of the Royal Society Edinburgh. 
Parallel Roads of Glen Roy,” published in the fourth volume of 
the Geological Transactions. The investigations of these able 
and accurate observers will, we trust, direct the attention of 
the philosophical geologist to this interesting part of Scotland. 
% On the Poisonous Fishes of the Carihhee Islands. By Wil- 
liam Ferguson, M. D. F. R. S- E. ; p. 65, — 80. 
An abstract of this paper -has already been given, in vol. i. 
p. 194, — 195. of this Journal. 
3. Account of a Mineral from Orkney. By Thomas Stewart 
Traill, M. D. F. R.'s. E. ; p. 81,-93. 
An abstract of this paper has already been given in this Jour- 
nal, vol. i. p. 380. 
4. Extract from an Inspection Report on the Mud Volcanoes (f' 
Trinidad. By William Ferguson, ,M. D. F, R. S, E. 
p. 93, — 96. 
The Mud Volcanoes described in this paper are situated near 
Point Icaque, the southern extremity of Trinidad. They oc- 
cur on a round bare platform of several acres, and resemble chim- 
neys like truncated cones, about three feet high, some of which were 
throwing out, with a strong bubbling noise, salt water, loaded with 
argillaceous earth. A white sea-shell was observed in the act of 
being thrown out along with the mud. The mud was always 
cold. In the hottest months of very dry seasons, the noise is 
said to be like that of the loudest dannons, and the mud is 
thrown up to the height of thirty feet. 
5. Memoir on the Repeating Reflecting Circle. By Major-Gene- 
ral Sir Thomas Brisbane, C. B. F. R. S. E.; p. 97,-102. 
The observations in this paper, were made with a repeating 
circle of Trough ton’s, six inches radius^ and divided on gold to 
20". For altitudes^ Sir Thomas chooses thirty repetitions, di- 
vided into three series of ten each, and reads the angle or arc 
run through during the series. For the time., he has always 
found six repetitions, sufficient to give it as correct as equal al- 
titudes ; aud of these lie generally observes three series in order 
to take the mean. Troughton’s circle, six inches radius^ gives the 
same results to a second, aS sl sixteenth inch repeating circle, with 
I) d 2 
