go Meteorological Journal. [Jan. 1814. 



REMARKS. 



Eleventh Month. — 16. A stormy night, after some rain. 17. Much wind, a. m.: 

 snow from 2 to 3 p. ni. which remained through the night. 18 A fine day: at 

 sun-set much rose colour, with Cirrostratus. 19. Overcast at 8 a. m., the barometer 

 falling: misty and drizzling. 22. Grey morning: fair day. 23. Misty, calm. 

 24. Overcast, drizzling. 25,26,27. Fine days. At sun-set on the 27th the wind 

 being S.E. the smoke of the city, in passing away in a body, swelled up into 

 several distinct heaps, each of which inosculated at ils summit with a small cloud. 

 This union was cle:irly the result of mutual attraction, and it continued for great 

 part of an hour. The clouds which at this time overspread the sky in great 

 uumbers were the remains of larger ones, which had in part evaporated, and now 

 resembled Cirrostrati : those which were attached to the smoke became sensibly 

 denset than the rest. 30. This month has exhibited an unusual proportion of fine 



davs. 



Tvcelfth Month. — 2. Gloudy ; a steady breeze : some light snow and sleet : rain 

 in the ni^ht. 3. Overcast : some rain. 4, 5. Cloudy, misty : rain at intervals. 

 8. a.m. small rain. 



RESULTS. 



Prevailing Winds, Easterly. 



Barometer: Greatest height 3018 inches ; 



Least 2902 inches; 



Mean of the period 29-723 inches. 



Thermometer : Greatest height SB" 



Least 25° 



Mean of the period .'. 39-6."' 



Evaporation, 0-37 inch. Rain, 077 inch. 



The latter part of this period has been remarkable for a general prevalence of 

 tlie diseases commonly attributed to obstructed perspiration. Tlie detail of these 

 beloBcs properly to the medical reports: it may, however, be suitable here to 

 point out the circumstances which appear to have contributed to this effect. I say 

 appear, because there undoubtedly e.^ist modifications of the air capable of 

 exciting disease, to the discovery of which none of the present mea .s of examina- 

 tion are competent. 



Tlie wind duringthe time alluded to, came in a moderate stream from the east- 

 •ward ; the barometer, which had been depressed, rising gradually. The sky was 

 almost constantly overcast with Cirrostratus; beneath which the atmosphere was 

 perceptibly full of diffused water, of the density of deic, quite down to the earth. 

 The sun's rays thus intercepted, the temperature varied little from 40° by day or 

 flight • and evaporation was nearly at a stand. Electricity in such circumstances 

 could' not accumulate: hence, though it drizzled at intervals, the air never got 



cleared by showers, , , . , , , . . 



Let us now apply these facts to the case. In health, the matter of perspiration 

 is thrown out on the skin in a fluid state, in quantity and with a force propor- 

 tioned to the state of the circulation in these respects. Here it has to evaporate in 

 the common way of fluids ; but it will do this very slowly, even at the common 

 temperature of the skin, in an air already loaded with moisture. In such an air, 

 too the whole muscular system being relaxed, the heart and arteries act with less 

 force. If it be, at the same time, only moderately cold, and void, in great 

 measure of light and electricity, it will want the exciting action of the nerves, 

 which results from the sudden loss of heat, as well as from the application of the 

 two latter stimuli. In a word, such an air, succeeding (o a dry and clear air, will 

 be a sedative: it will counteract, by constant, thouj;h inieusible, effects, the 

 healthy energies even of the strong. The usual sponging operation on the skiu 

 being withheld, at the same time that the vis a tergo is lessened, we need not 

 wonder that the matter of perspiration should stagnate in the fine extremities of 

 Hie cuticular arteries, or be thrown on some internal secreting surface ; that the 

 skin should take on a stale of spasm, and that fever and local inflammation should 

 ensue. Thus, without supposing in this case any occult quality in the air, we may 

 trace a combination of qualities which may be reasonably liiougbt to have made it 

 productive of disease. 



Tottenham, Twelfth Mvnth, 23, 1813. L. HOWARD. 



