real interest; but for the most part Faith found
the exhibition was for her and she and the doctor might have it all
their own way. A long way they made of it; for the doctor found a good
deal of talking to do, and Faith was most ready to hear. He talked well
and gave her a great deal of what she liked, with a renewal every now
and then of his first surprise; for in the midst of some elaborate
explanation he was launching into for her benefit, most innocently and
simply Faith would bring him up with a gentle "Yes, I know,"--not
spoken with the faintest arrogance of knowledge, but merely to prevent
him going into needless detail; and herself too rapt in the delight of
the subject that occupied her to have any heed of the effect of her
words.

"I have kept the best for the last," said the doctor, when this
exhibition had lasted a much longer time than Faith was aware of;--"I
thought you would like to see the circulation;--and I have sent all
over town for a frog--found one at last, by great happiness."

"All over town!" said Mrs. Somers,--"do try out of town next time, and
save yourself trouble."

"Have you got to kill the frog, Julius?" said Miss Harrison with a
disturbed face.

"I hope not!" said the doctor gravely. "That would rather interfere
with our purposes than otherwise, Sophy.--Aunt Ellen, I never learned
the real extent of 'town' yet--when I was a boy it seemed to me to have
no limits;--and now it seems to me to have no centre. Tell James to
bring in that frog, Sophy."

Miss Harrison retreated from the frog; but the doctor assured Faith
that he was in very tolerable circumstances, shut up in a little bag;
and that he was only going to be requested to exhibit a small portion
of the skin of his toe, and to hold himself still for that purpose;
which benevolent action the doctor would help him to perform by putting
him in a slight degree of confinement. The holding still was however
apparently beyond the frog's benevolent powers, and it was some little
time before the doctor could persuade him to it. Then Faith saw what
she had never seen nor fully imagined before.

"O Sophy!--O Mrs. Somers!"--she exclaimed,--"look at this!"

She stood back with a face of delighted wonder Miss Harrison looked an
instant.

"It is curious--" she said. "What are those little things, Julius?"

"You have heard of the 'circulating medium,'" said the doctor. "That is
it."

Faith evidently had never heard of the 'medium' refer