Observations in the North Atlantic. 357 



the temperature of the air 65^-0, aud the dew-point 62°-0 ; the 

 following morning* the wind was N. by E., the temperature 

 of the air dS^'i only, and the dew-point 46°"6, while the tem- 

 perature of the sea at noon was 62°'3. Here the passage of the 

 cold air from the northward is obvious enough, and, as is usual 

 in gales in the northern hemisphere, the wind, the same even- 

 ing and following day, gradually backed round to the westward, 

 and blew hard. On the afternoon of the 27th, the ship being 

 then just on the edge of the colder water, the wind again came 

 to the north, and freshened rapidly from the same point towards 

 evening ; about 9 P.M. its force was 10 ; during the night it 

 gradually backed round to the north-westward, blowing hard, 

 just as in the previous instance. In these two cases the ship 

 was in the northern part of tlie gale ; but, on the 2d March, 

 another was experienced from SSAV., which, by the following 

 morning, had veered to NW. by W., the southern part of which 

 only had passed over her. 



Mr Battersby experienced similar weather between lat. 43° 

 and 47° N., from the 20th to the 24th September 1841 ; and 

 the shipping iiitelligence of every year contains abundance of 

 ■evidence of the same description. 



On the occurrence of Phosphoric Acid in Simple Minerals and 

 Bocks. 



Dr Fownes of London, in a published memoir, announced 

 that he had discovered phosphoric acid in rocks generally be- 

 lieved to be of igneous origin — as in the gx-ey vesicular lava 

 from the Rhine, the white trachyte of the Drachenfels, in 

 basalts, porphyritic lava of Vesuvius, and in volcanic tufa from 

 the same mountain. Professor C. Kcrsten of Freyberg, how- 

 ever, declares that he was unable to detect the least trace of 

 phosphoric acid in such rocks. In the September number of 

 the Philosophical Magazine (year 1845), Wm. Sullivan, Esq., 



• The moon was in perigee on the 24th, and full at -t L. 15 m, a.m. 

 on the 25tlu 



