Royal Physical Society of Edinburgh. 3893 



presence in this instance might lead to its detection in oak timber previous to its being 

 employed for building purposes. 



March 23, 1853. — George Jackson, Esq., President, in the chair. 



A paper by Dr. Wm. Gregory, F.K.S.E., Professor of Chemistry in the University 

 of Edinburgh, intituled, " Notice of a Diatomaceous Earth found in the Isle of Mull," 

 was read. The author commenced by stating that this earth was discovered about 

 two years ago by the Duke of Argyll, who gave a short account of its geological posi- 

 tion to the Royal Society of Edinburgh. It constitutes a bed, resembling marl in ap- 

 pearance, lying in a rough piece of ground at Knock, near Aros, between Loch Baa, 

 a fresh-water lake, and the sea. It is extremely rich in Diatomaceous remains, con- 

 taining (according to a synopsis sent with the paper) various species of the genera 

 Pinnularia, Navicula, Gomphonema, Amphora, Stauroneis, Cocconeis, Durirella, 

 Cynibella, Himantidium, Tabellaria, Epithemia, Eunotia, Synedra, Frayilaria, and 

 Orthosira. The most remarkable for their abundance are the genera Pinnularia, Na- 

 vicula, and Stauroneis; and many of the species of these and of the other genera are 

 of great rarity. After giving the chemical analysis of this earth, the Professor con- 

 cluded by stating that the Mull deposit appears to him to be richer in Diatomaceous 

 species, and perhaps also in genera, than any other known deposit, there being at least 

 sixty species and sixteen genera enumerated as having beeu found in it. A portion 

 of the earth, and some slides containing specimens, accompanied the paper, — /. W. 



Proceedings of the Royal Physical Society of Edinburgh. 



Saturday, February 12, 1853. — Hugh Miller, Esq., President, in the chair. 



The first communication laid before the meeting was — " On some Insects from the 

 Rocky Mountains, received from the Botanical Expedition to Oregon under Mr. Jef- 

 frey," by Andrew Murray, Esq., W.S. After alluding to the principal object of the 

 Expedition, and describing some of the new Coniferae, the seeds of which have been 

 sent home, Mr. Murray said that when the Association was first started, he suggested 

 to the Committee of Management that an addition might be made to its funds by ad- 

 mitting a limited number of entomologists, to receive beetles instead of seeds. In 

 spring and early summer there would be few or no seeds to collect, while that was the 

 very best season for insects ; and at other times the collecting of the two might be 

 made compatible, by instructing the collector to make the seeds his principal, and the 

 insects only his subordinate object. The Committee adopted the suggestion, and the 

 allowed number of entomologists immediately came forward. Unfortunately, Mr. 

 Jeffrey was not an entomologist, and consequently, although he has no doubt done 

 his best, only a very small supply of insects has yet been received. These consist of a 

 few taken near York Factory and on the way to the Rocky Mountains, a few taken at 

 Jasper House on their east flank, and the rest on the west flank. 



Mr. Murray handed round a box containing the specimens which fell to his lot, 

 with the insects from the different quarters placed slightly apart. Those in the first 

 detachment were taken near York Factory (the nearest point to this country visited by 



