208 TRANSACTIONS OF THE [may 7%, 
Dr. Priestley, while suffering an enforced separation from the 
society of his fellow-philosophers, was not forgetful of them, 
and in 1793 he dedicated his treatise, ‘‘ Experiments on the 
Generation of Air from Water,” to his ‘‘ valued friends, the 
members of the Lunar Society at Birmingham.” In this dedi- 
cation, he says: ‘‘ There are few things I more regret, in con- 
sequence of my removal from Birmingham, than the loss of 
your society. It both encouraged and enlightened me, so that 
what I did there of a philosophical kind ought in justice to be at- 
tributed almost as much to youas to myself. From our cheerful 
meetings I never absented myself voluntarily, and from my pleas- 
ing recollection they will never be absent. Should the cause of our 
separation make it necessary for me to remove to a still greater 
distance from you, I shall only think the more, and with the 
more regret, of our past interviews.” ‘‘ Philosophy,” he adds, 
*‘engrossed us wholly. Politicians may think there are no ob- 
jects of any consequence -besides those which immediately in- 
terest them. But objects far superior to any of which they have 
any idea engaged our attention, and the discussion of them was 
accompanied with a satisfaction to which they are strangers. 
Happy would it be for the world if their pursuits were as tran- 
quil, and their projects as innocent and as friendly to the 
best interests of mankind as ours.” Finally, he concludes by 
earnestly committing them all, though in religious persuasion 
differing from himself, ‘‘ to the protection and blessing of that 
Great Being whose we are, and whom I| trust we all serve, aud 
who established that course of nature which is the object of our 
common investigation.” And then the Rev. Doctor prays 
“with the greatest esteem and affection ” for a happy reunion 
with them all in another state of being. 
On another occasion, Priestley, writing to Watt, again ex- 
pressed his affection for the members of the society in graceful 
language. After thanking Watt and Boulton for the gift of a 
copving machine (invented by the former), the doctor adds: 
‘¢This and many other things will ever remind me of the obli- 
gations I am under to you, and the pleasing intercourse I have 
had with you and all my friends of the Lunar Society. Such 
another I can never expect to see. Indeed, London cannot fur- 
nish it. I shall always think of you at the usual times of your 
meeting.” (Letter of November 2d, 1791.) 
Even after his settlement in Northumberland, the doctor 
continued to communicate his scientific observations to his 
friends in the Lunar Society. On December 6th, 1795, writing 
to his friend the Rev. Theophilus Lindsay, Priestley explains 
that he forwards through Dr. Young a copy of a paper prepared 
for the Philosophical Society at Philadelphia, and says: ‘‘ Please 
