m> Dr. Bostock on Whale Oil [Jak. 



received by gauges at different heights from the surface of the 

 earth. I do not mean to enter into the controversy with respect 

 to the direction of the drops : this I shall leave to Mr. Meikle 

 and his antagonists, but there is another part of the question 

 which seems to have been overlooked, and to which, therefore, 

 I could wish to call the attention of your readers. 



I am persuaded by private observations, as well as by those 

 which have been made public, that the fact is certainly true of 

 more rain falhng near the earth*s surface than at some height 

 above it. This seems to be a paradox, and many have, there-' 

 fbre, endeavoured to explain it away, but still it seems to me to 

 be a necessary consequence of the very constitution of the atmo-' 

 sphere. Clouds collect before rain falls, but this is not in con-' 

 sequence of their being the only source of moisture, but of the 

 upper strata of the air being first affected by those causes 

 which produce the rain. The quantity of rain is made up of a 

 general discharge of water from the air between the earth and 

 the region of the clouds. Hence the effects must accumulate 

 as we approach to the earth, and the results which have been 

 dbserved must not be wholly attributed to the wind, or to any 

 accidental circumstances which may affect the instruments 

 which are used for the admeasurement. N. 



Article XI. 



^ome Observations on Whale Oil. By J. Bostock, MD. FRS. 

 LS. and HS. MRI. Mem. of the Med., Geol., and Astron. 

 See. &c. &c. 



Great Coram-street, Dec. 21, 1820. 



The object of this communication is to give an account of 

 some experiments in which I was concerned that were made in 

 order to ascertain the changes that are produced in oil by expos 

 ing it for a length of time to an elevated temperature.* With- 

 out going into a minute detail of the individual experiments, I 

 shall state some of the most important of the results, and shall 

 afterwards offer a few observations upon the nature of the pro- 

 cess and upon the mode by which the change is effected. The 

 quantity of oil operated upon was generally from 25 to 30 gal- 

 lons ; the fluid was contained in a boiler three feet long, one foot 

 six inches wide, one foot three inches deep; fire-place 14 inches 

 long, three inches wide ; the bars three inches from the bottom 



* The experiments were performed at the manufactory of I^Iessrs. Taylors and 

 lHartineau, in the presence of several scientific gentlemen : among others, of Mr. Chil- 

 dren, Mr. Aikin,' Mr. Daniell, Mr. Richard Phillips, and Air. Faraday. 



