98 Dr Stark on the Influence of Colour ofi Odours. 



were smothered.*" Lord Bacon attributes this effect to the 

 smell of the jail, where the prisoners had been close and nastily 

 kept ; and mentions it having occurred twice or thrice in his 

 time, " when both the judges that sat upon jail, and'numbers 

 of those who attended the business, or were present, sickened 

 and died." * A similar occurrence related by Sir John Pringle, 

 happened at the Old Bailey sessions in 1750, when four of the 

 judges were attacked and died, together with two others of the 

 counsel, one of the under sheriffs, several of the jury and others, 

 to the amount of about forty in the whole. My explanation of 

 the peculiar fatality of these emanations to the judges, counsel, 

 and jurors, was the peculiar attraction of their official black for 

 the putrid effluvium, as Sir John calls it ; and the escape of two 

 of the judges who sat on one side of the Lord Mayor, to the 

 current of air that was in the room not sending the baneful 

 odours in their direction. 



On finding the Dew-Point, S^cjrom the Cold induced hy the 

 Evaporation of Water, By H. Meikle, Esq. Commu- 

 nicated by the Author. 



I WAS happy to see this interesting subject taken up, and so 

 much forwarded, in this Journal for September last. The for- 

 mula and table there given for obtaining the dew-point from 

 the temperature of the air and depression of the moist thermo- 

 meter, agree so well with observation, so far as the comparison 

 has been made, that they appear to be by far the most accurate 

 that have yet been given for the purpose ; but it is much to be 

 wished that observations were furnished for verifying them, for 

 temperatures above 92° and below h^"", the limits of the range 

 compared. A perusal of that article, and of the observations or 

 experiments adduced in it, led me to revise and compare with 

 them a scheme, which had occurred to me about seven years 

 ago, for obtaining the dew-point from the same data, by merely 

 laying a ruler across certain lines or curves delineated on a 

 plane. From some rude sketches which I had then made, it 

 appeared that this object could be effected by means of straight 

 lines together with curves, which very much resembled hyper- 

 bolas ; but I had not then ascertained that the common or conic 

 • Priijgle's Observations on Diseases of the Army, p. 296. 



