EXAMINED. 267 



already observed that the heat employed there for 

 green tea seems to me of too low a temperature, 



Before closing these remarks on the heat employed 

 at Java, it is necessary to observe that in repeating 

 the experiment by which Mr. Jacobson determines 

 the heat required, his results and mine do not 

 coincide. 



It is first remarked by him, that the thermometer 

 must not be used to determine the amount of heat. 

 The roaster should from habit be able to determine 

 that, by holding his hand one inch above the vessel 

 while he can count twenty. Now I heated a 

 roasting vessel to 350° of Fahrenheit, determined 

 by placing the bare bulb of a thermometer in 

 contact with the iron, and in the centre of the pan, 

 or the part most heated. Another thermometer, 

 also with the bulb exposed, was held even with the 

 edge of the pan also over the centre, and it marked 

 only 180° of heat. With my hand held in this 

 position so long as I could bear it I deliberately 

 counted thirty. At 315°, the upper thermometer 

 marked 150°: at 300° the upper thermometer 

 marked 145°: and in order to guard against all 

 suspicion of error, I placed a piece of wood across 

 and resting on the edges of the pan. Then with 

 my hand held first above, and then below the 

 wood, I counted one hundred, and felt no incon- 

 venience. 



Now I do not mean here to impugn in any 

 degree the accuracy of Mr. Jacobson's experiment. 



