314 Proceedings of Philosophical Societies. [Oct. 



■moisture, is nearly the reverse of that prevailing in the Cape 

 peninsula ; the number of rainy days throughout the year were 

 76 ; 15 only of which occurred during the winter months. The 

 general direction of the winds NW, or SE : and the annual table 

 gives 135 days on which northerly winds prevailed ; .179 days of 

 southerly winds ; 2 1 westerly ; and 1 1 easterly. The latter winds 

 are often accompanied with a great mortality among horses. 



Dr. Knox next demonstrates, that the climate of°the Cape is 

 not favourable for those of consumptive habits, though in other 

 respects extremely salubrious. 



In the second part of the paper a table is given, showing the 

 temperature of the air and of the ocean between the latitudes of 

 50° 2' and 20° 24' TX, and longitude 7° 7' and 24° 27' W. The 

 table and annexed observations confirm the remarks of Peron, 

 Humboldt, and others, and establish, beyond all doubt, the 

 remarkable equability of temperature observable in atmospheric 

 air resting over the great ocean. To this quality in the air above, 

 the author ascribes the advantages derived by the phthisical in 

 long voyages ; and the total inutility of sailing along a coast, or 

 in the immediate vicinity of any land. 



Finally, from observations made on that peculiar climate, call- 

 ed by sailors "The Rains," compared with what he has seen 

 in other countries, Dr. Knox is of opinion, that the doctrines 

 regarding marsh miasmata, and their noxious effects on the 

 human frame, are problematical, and moreover unnecessary in 

 explaining those deleterious effects, which he thinks are ascrib- 

 able to the combination of heat and moisture only. 



The reading of Professor Agardh's paper, on the Metamor- 

 phosis of Algae, was concluded. It is impossible by any abstract, 

 however copious, to do justice to this important paper. The 

 details are minute and interesting ; and the facts introduced in 

 support of these are numerous and valuable. It will soon appear 

 in the Transactions of the Society, which we understand it is in 

 contemplation to publish quarterly, or half-yearly. 



Mr. Falconer read a notice regarding the Tulipa Oculus Solis, 

 and another beautiful flower, of which drawings were exhi- 

 bited. 



Mr. John Deuchar read a paper, containing Observations on 

 the Occasional Appearance of Water in the Cavities of regularly 

 shaped Crystals, and on the porous Nature of Quartz, and other 

 crystalline Substances, as the probable Cause of this Circuit 

 stance. In this paper he supposes that natural and artificial 

 crystals have a similar origin, and that although the former pos- 

 sess a peculiar compactness of cohesion and tardiness of solu- 

 tion, which do not belong to the latter, yet that the artificial ones, 

 through length of time, would acquire a similar cohesion 

 and insolubility. Mr. Deuchar holds, that the water of crystalli- 

 zation in artificial crystals is in great excess, and that this excess, 

 under certain circumstances, gradually decreases. He holds, that 



