OP LA PEROUSE. 59 



loaded without fuch a heat, that every thing that 

 js not expofed to the fun is affecled by great hu- 

 midity; it is, for this reafon, very difficult thereto 

 preferve from rufl iron infiruments, and even the 

 beft polifhed fteel. 



During the whole time that we remained 

 between the tropics, the mercury in the barome- 

 ter had not rifen above 28 inches 4 lines, and it 

 had not fallen below 28 inches 1^ line. 



We were well aware that our flock of water 

 would not preferve its purity in the fuffocating 

 heats which we experienced ; but it would have 

 been difficult to prefume, that, having on board 

 fome means very eafy to be adopted for fweeten- 

 ing the water, before the daily allowance was 

 ferved out, thefe means would not have been 

 effectually employed. 



The water kept on fhipboard, undergoes in 

 long paffages the fame decompofition as ftagnant 

 waters, and this decompofition is Angularly ac- 

 celerated by the heat of the climate. There then 

 arifes from it fo great a quantity of inflammable 

 air, that a perfon runs a rifk of being fuffocated 

 in going down into the hold where it is depo- 

 sited. This accident however is very uncom- 

 mon, becaufe the opening which leads thither, 

 allows part of thefe noxious miafmata to efcape. 

 It is not the lefs true, that thefe often produce 

 nervous fevers, the malignity of which is propor- 

 tionate 



