VOL. LVII.] PHILOSOPHICAL TRANSACTIONS. 423 



XXF. On the Heat of the Climate at Bengal. By Fleming Martin, Esq. 

 Chief Engineer at that Place, p. 218. 



The intense and uncommon heat in this climate has been for some time past 

 almost insufferable. The thermometer was seldom under 98, and the quick- 

 silver rose at certain times of the day to 104° by the best adjusted instrument; 

 he was even assured by some gentlemen, that in the camp, 500 miles distant, 

 the thermometer often stood at 120; but such a difference might be occasioned 

 by the badness of the instrument. However, nothing could exceed the intense 

 heat felt day and night, during the month of June. May and July were little 

 inferior at times, but affordal some intermission ; otherwise a very great morta- 

 lity must have attended this settlement, though they were not without instances 

 of fatal effects in the month of June, when some few individuals in sound health 

 were suddenly seized, and died in the space of 4 hours. 



The rains have set in since the 4th of June. This is called the unhealthy 

 season, on account of the salt-petre impregnated in the earth, which is exhaled 

 by the sun, when the rain 'admits of intervals. Great sickness is caused by it, 

 especially when the rains subside : which generally happens about the middle of 

 October. The air becomes afterwards rather more temperate, and till April per- 

 mits of exercise, to recover the human frame, that is relaxed and worn out by 

 the preceding season ; for in the hot periods every relief is denied, except rising 

 in the morning, and being on horse back by day break, to enjoy an hour, or little 

 more, before the sun is elevated ; it becomes too powerful by 6 o'clock to with- 

 stand its influence ; nor can the same be attempted that day again till the sun re- 

 tires ; so that the rest of the 24 hours is passed under the most severe trials of 

 heat In such season it is impossible to sleep under the suffocating heat that ren- 

 ders respiration extremely difficult ; hence people get out into the virandos and 

 elsewhere for breath, where the dews prove cooling, but generally mortal to such 

 as venture to sleep in that air. In short, this climate soon exhausts a person's 

 health and strength, though ever so firm in constitution, as is visible in every 

 countenance, after being here 12 months. 



XXVI. Experiments on the Peruvian Bark. By Thomas Perctval, M. D., 



F.R.S. p. 221. 

 May be consulted in this author's Medical and Experimental Essays, in 2 

 vols. Svo. 



XXVII. An Inquiry into the Probable Parallax and Magnitude of the Fixed 

 Stars, from the Quantity of Light which they afford us, and the Particular 

 Circumstances of their Situation. By the Rev. John Michell, B, £)., F. R. S, 

 p. 234. 



Though no man can at present doubt, that the want of a sensible parallax in 



