M. BeuJaiit on tJu) Natron Lakes of IltLngmy, ifc. ^25^ 
Mean Temper aiitre of Months for 
January, 
- 
74.0 
J\ily, 
February, 
75.0 
August, 
March, 
- 
75:1 
September, 
April, 
- 
74.9 
October, 
May, 
- 
76.7 
November, 
June, 
- 
80.2 
December^ 
Mean temperature of the year 1820, 
Mean of the years 1819 and 1820, 
79.5 
79.0 
80.3 
79.3 
77.8 
74.8 
77,2 
77.5 
Mean temperature calculated from Dr Brewster’s formu- -w 
la *, on the supposition of two poles of maxin^um cold, J 
Difference between the observed and calculated mean temperatures, 
75.08 
2.42 
This difference is obviously owing, in a considerable degree, 
to the circumstance, that observations made at sun-rise and noon, 
give a temperature higher than the true mean temperature of 
the day. 
When we consider that the climate of Port Antonio is in- 
sular, and, therefore, cceteris paribus, warmer than a conti- 
nental one, it is manifest that it is considerably tempered by the 
influence of the transatlantic pole. 
The mean temperature of Kingston, on the south side of the 
island, has been estimated at 80 ° of Fahrenheit. 
Art. XIII . — Account of the Natron Lakes f Hungary, of the 
Pitchstone (f Trihisch in Saxony, and the Mineralogical 
School of Freyherg. By J. S. Beudant, Chevalier of the 
Legion of Honour, &c. &c *|*. 
Natron, which in Hungary is named Szek so (sel de la- 
trine), because it was at first confounded with saltpetre, occurs 
in great abundance in the neighbourhood of Debretzin, where 
it is contained in solution in the marshes and lakes which ex- 
tend on all sides into the plain. It is found all along, in greater 
or less quantity, from the plains of Szathmar to those of the 
counties of Bacs and Pest, as well as in those of Stuhlweissen- 
* Namely, T rz 86®,3 sin (D---3|°) ; D being the distance from the transatlan- 
tic pole. The Long, of Port Antonio is about 76° 5' W., and the Lat. 18° 5' N. 
See Edinburgh Transactions, vol. ix. p. 215. ' 
From his Travels in Hungary, just published in Paris. 
t 
