Humid Climate of Ireland. jpg, 



less strong in the siik and sti'ong, supposing tliat it was either, 

 exhaled, its communication with tiie. 

 exterior air not having been intercepted 

 by the water, or arising from some other 

 cause, not at present to be defined. 



The funiigation being performed, as 

 in tlic iiiiitJi experiiueut, on ail th« 

 sub»timces, the paper produced tho 

 same reiiult. 



JEleveatJi expeiiment. — I performed 

 the ojjeratiou on letters containing pa- 

 per, siik, wool, cotton, and hemp, in- 

 fiected by iLe same process. I ai lowed 

 them to reiiiaia in tije stove for one 

 nigiit ; on tlie Ibllowiug day all those 

 substajjcefc saiolt of tlie chloriue, and 

 had lost the cadiiveroiis smell. 



This eipeiiiiiCiit, in coutinning tb« 

 last coiJclu«iioii of tlie eightli experiment, 

 indicates, at the same time, a eircum- 

 eiauce whidi ought to be observed ia 

 tLe disinfection of letters, according to 

 tlie process of M. iVforveau. 



I <,jught, however, to premise, that 

 cither tiom the exhalation of tlie chlo- 

 rine not beiJig unitoriu, or the letter^ 

 not being equally exposed to its actfoa, 

 the result of this process is not always 

 the same. It might, therefore, hap[;en, 

 tliat in fumigating letters some may 

 remain, in which the operation has been 

 but badly or partially peiformed ; and it 

 is nevertheless iiecessary to find th# 

 critewon of disinfection of letters b^ 

 tliis process. 



To the Editor of t/te Monthly Magazine. 



SIR, 



HAVING lately met with the fol- 

 lowing obseiTations in your ex- 

 cellent miscdhuiy — 



"Itia detei-niined, by observation, that 

 the mean animal quantity of rain is greatest 

 at the equator, and decreases gradually 

 as we approach the poles, thus — 



I8l6.] 



the skin, 



wool, and still less so in the cotton and 



the hemp. 



I inclosed in twelve letters these six 

 substances, infected with cadaverous 

 odour. I made two incisions in each 

 of these letters, of about an inch and a 

 half. TIjc fumigation was performed 

 as in the third experiment, and, alta- 

 half an hour, the letters Were taketi 

 from the stove. On examining imme- 

 diately these six letters, which enclosed 

 the six different infected substanceg. 

 Doctor Seixas, the servant of tlie labo- 

 ratory, and myself, were fully agreed, 

 that the hemp ouly preserved the odow 

 of the chlorine, that the cotton \\&s 

 absolutely free from it, that tlie featLci-s 

 and the skiu still smelt sliougly of the 

 putrefied flesh, and tliat the odour wae 

 weaker in the silk, and still weaker- in 

 tlie wool. 



On examining the other six letters, on 

 the following day, I observed, tiiat the 

 cotton and the hump smelt of tlie clilo- 

 rine, and not of the putrefied meat, the 

 smell of wiiich was scarcely perceptible 

 in the silk and the wool, and still suili- 

 cieutly determinate in tlie feathers and 

 the skiu. 



I concluded, from this experiment, 

 that the animal .substances, at least 

 feathers and skins, imjiregnate tliem- 

 selves more with the cadaverous odour 

 than vegetable substances; that the lat- 

 ter lo.se it altogether, or are easily pu- 

 rified from it; tiiat the efiect of the fu- 

 migation is less at the close of the ojk;- 

 ration, than on preserving the letter 

 sealed until the following day: finally, 

 tliat animal substances require an a<> 

 tion of greater duration and intensity 

 than fumigation. 



I'o verify this latter conclusion, 



Ninth experimetU — I placed on a 

 paper, pricked with a pin, these animal 

 substances, uifectcd with the cadavcroug 

 gas. I performed the fumigation on 

 the outside of the stove, by suspending 

 the paper two inches above the fumi- 

 gating cup; i:i five minutes afterwards, 

 the bad smell was not perceptible in 

 any of them. 



Tenth exjjeriment. — I infected, as in 

 the nintli experiment, the same sub- 

 Btanecs and the paper ; the following 

 differences were always apparent in ti>is 

 infection : — 



First, there was not the half ounce of 

 water, which in the ninth experiment 

 nioisileiu'd considerably the substances 

 MUsceptible of infection, 



iiecondly, the bad odour was not so 



I think that, in a calculation of Uiis'ila- 

 ture, allowance sliouJd be made for 

 longitude as well as for latitude, or ra- 

 ther indce-d for locality; thus, Irelaad, in 

 Ci2, being so much to tlic westward, and 

 so near tlie exhalations from tJic great 

 body of the Atlantic, receives nearly as 

 much rain as Rome in 41, and mor« 

 thai) any interior district in Spain ; 

 Italy, being so narrow a peninsula, has 

 ten times tlie wet of Kgypt ; and Cal- 

 cutta, in latitude 22° 12.3' north, has 



aiorc 



