5<d Dr. dobson’s Account of the Harmattan, 
four or five days, the fcarf (kin peels off, firft from the hands 
and face, and afterwards from the other parts of the body, if it 
continues a day or two longer. Mr. norris obferved, that 
when fweat was excited by exercife on thofe parts which were 
covered by his cloaths from the weather, it was peculiarly 
acrid, and tafted, on applying his tongue to his arm, fome- 
thing like fpirit of hart’s-horn diluted with water. 
As the {fate of fait of tartar placed in the open air, and the 
quantity evaporated from a given furface of water, are obvious 
proofs of the comparative moifture or drynefs of the atmofphere, 
I defired Mr. norris to put the Harmattan to each of thefe 
tefls ; and particularly to moilten fait of tartar^ Jeliquium , and 
expofe it to the night air during the time that the Harmattan 
was blowing. The following is the account of the refult of 
thefe experiments. Salt of tartar will not only remain dry 
during the night as well as in the day ; but, when liquified fo as 
to run upon a tile, and expofedtothe Harmattan, becomes per- 
fectly dry in two or three hours ; and, expofed in like maimer 
to the night air, will be dry before morning. 
With refpeCt to evaporation Mr. norris fays, “ I fixed the 
u tin veffel, with which you favoured me, on a grafs plat 
u behind my houfe, upon a {land four feet high, and expofed 
“ by its fituation mo{f part of the day to the fun, but fhel- 
“ tered in fome meafure from the wind by the houfe.” 
Day 
'i 
