106 
those also which we had an account of from England, adding a 
number of new ones. I say much practice, for my house was con- 
tinually full for some time with persons who came to see these new 
wonders. ‘To divide a little this incumbrance among my friends, 
I caused a number of similar tubes to be blown in our glass house, 
with which they furnished themselves, so that we had, at length, 
several performers. Among these, the principal was Mr. Kinnersly, 
an ingenious neighbor, who, being out of business, I encouraged to 
undertake showing the experiments for money, and drew up for 
him two lectures in which the experiments were ranged in such 
order and accompanied with explanations in such method as that 
the foregoing should assist in comprehending the following. He 
procured an elegant apparatus for this purpose, in which all the 
little machines that I had roughly made for myself were neatly 
formed by instrument makers.’’* He continues: ‘‘ Obliged as we 
were to Mr. Collinson for the present of the tube, etc., I thought 
it right he should be informed of our success in using it, and wrote 
him several letters containing accounts of our experiments.’’ 
Franklin’s first letter to Collinson is dated July 11, 1747. In it 
he says: ‘* We rub our tubes with buckskin and observe always to 
keep the same side to the tube and never to sully the tube by hand- 
ling; thus they work readily and easily, without the least fatigue, 
especially if kept in tight pasteboard cases, lined with flannel and 
fitting close to the tube.’’ In a footnote he adds, ‘‘ Our tubes are 
made here of green glass, 27 or 30 inches long, as big as can be 
grasped.”’ 
* Memoirs of the Life and Writings of Benjamin Franklin, LL.D., F.R.S. Written by 
himself to a late period and continued to the time of his death by his grandson, William 
Temple Franklin. Third edition, in six yolumes. London, 1818. Vol. i, p. 237. 
+ New Experiments and Observations on Electricity, made at Philadelphia, in America, 
by Benjamin Franklin, LL.D and F.R.S. London, 1769. Franklin himself says of these 
letters: ‘‘ Mr. Collinson gave them to Cave for publication in his Gentlemen's Magazine ; 
but he chose to print them separately in a pamphlet and Dr. Fothergill wrote the Preface.”’ 
In this Preface Dr. Fothergill says : ‘‘ The experiments which our author relates are most 
of them peculiar to himself; they are conducted with judgment and the inferences from 
them plain and conclusive ; though sometimes proposed under the terms of suppositions 
and conjectures. .... 
‘“‘ He exhibits to our consideration an invisible, subtle matter, disseminated through all 
nature in various proportions equally unobserved, and, whilst all those bodies to which it 
peculiarly adheres are alike charged with it, inoffensive. 
‘He shows, however, that if an unequal distribution is by any means brought about; 
if there is a coaceryation in one part of space, a less proportion, vacuity or want in 
another; by the near approach of a body capable of conducting the coacervated part to 
the emptier space, it becomes, perhaps, the most formidable and irresistible agent in the 
universe. Animals are in an instant struck breathless, bodies almost impervious by any 
force yet known are perforated, and metals fused by it in a moment.” 
