JEFPECTS OF THUNDBE. ' 123 



This tremor, fo communicated, may in my opinion be the Which may pro- 

 commencement of that inlenfible or rather imperceptible agi- j^enclmentof 

 lation neceffary to the produftion of the different fiates of fer- the fermenutrrc 

 mentation, which when once began, may be corjiinued, pro- ^g'tation. 

 vided the circumftances of temperature, &c. be equally fa- 

 vourable as atfirlL Now we perceive that this motion ispro^ 

 duced by found;* and a fonorous body lofes this vibration on 

 being touched, and the found itfelf of courfe ceafes. In like 

 manner the inteftine niotion arifing from the vibration occafion- 

 ^d by the noife of thunder, being prevented from taking place 

 ,)by the conta6t of the fufpended Itones with the fides of the 

 ; /cafk, the enfuing fermentation cannot commence, and the beer 

 ^is preferved from running into the acetous fermentation. 



This infenfible motion is alfo neceflary to affift the abforb- 



^ jtion of oxygen, without which neither beer can grow four, 



^ nor can cream become rancid ; for violent agitation will not 



produce the like effed even though accompanied or affifted 



• yvith the neceifary increafe of temperature. 



It was alfo obferved by the gentleman with \yhom I was con- Decompofition 

 yerfing on this fubjecl, that butter by being overmuch waflied of water or ay: 

 or wrought in water Ipfes cpnfiderably of its yellow colour, 

 and acquires in a great meafure the palenefs and confidence of 

 tallow. It might be worth while to ipake fome experiments 

 in this way, how far animal oils or fat are capable pf decom- 

 pofing atmofpheric air or water. The circumftances jiecef- 

 fary to determine Ihe mutual change on each, are agitation, and 

 a frequent change of furface. The abforption of oxygen 

 would takp place in both cafes, the refiduum of atmofpheric 

 air being azotic gas, and that of water hydrogen gas. I had 

 found by experiments, and that fome time before I favv the 

 circumftance publicly noticed, I may fay, even before the new 

 theory of chemiftry was promulgated, that the union between Rancid oils com« 

 piercury and the fat with which it was combined in the com- ^'"<= ^®"«*" W'lJ^ 

 pofition of the ointment, became much more intimate and ^efli"'^ 

 perfed on being kept for fome time, and that the rancidity, 

 which I thought arofe from the developement of fome peculiar 

 acid, was prevented from becoming fenfible by that acid being 

 abforbed by the metal. From thispircumftanpe, and from this 

 fuppofition, I was Jpd contrary to the diredions and cqmmands 



f J mean among other caufcs producing it. 



of 



