[ 3 6 9 ] 
The feries of my experiments, however inconsi- 
derable they may prove in the refult, have taken a 
turn I did not at fir ft forefee. I fet out with inquir- 
ing into the nature of an electricity, that feemed to 
have fome connexion with the human body : I had 
made but little progrefs when I was furprifed with an 
appearance of electricity, arifing from the contraft of 
two colours, or coloured bodies of the fame fub- 
ftance: I met with it in my experiments, perpetual- 
ly pofitive and negative ; and under that appearance 
have followed it through a variety of its operations. 
The notions it hath led me to conceive, are different 
from thofe I had before entertained of electricity. 
Such as they are, they fhall, in due time, be freely 
Submitted to the judgment of the Society. 
Having been told by one or two of my friends, that 
they had tried fome of the experiments mentioned in 
the preceding papers, but could not get them to fuc- 
ceed ; I beg leave to add a few words, before I con- 
clude, by way of caution to any, who may have a 
curiofity to verify my experiments. 
However eafy it may feem to be, to follow the di- 
rections I have already given in electrifying the lock- 
ing, I am fenfible from my own experience, that an 
attention to a number of little circumftances, befides 
fome fmall degree of addrefs, is requifite, in order to 
make it fucceed readily. This is known to have been 
the cafe with the eleCtrical tube and globe : few peo- 
ple, at firft, knew how to manage them fuccefsfully; 
and yet glafs is not fo much expofed to many incon- 
veniencies, that affeCt electricity, as filk. To give 
but one inftance of this : we know that a very fmall 
quantity of duft, greafe, or any other matter that 
Vo l. LI. Bbb flicks 
