eep
sherry colour a few hours after being made. This must have depended upon
the free iodide it contained, and yet such collodion has worked most
admirably. I have now before me a large body of collodion almost red, and
which has been made some three or four months; yet the last time I used
this, about a week since, it was just as good as when it was first made.
Undoubtedly collodion does more or less deteriorate with age; but here I
would observe, that there is an immense difference in the different
manufactures of collodion, and which can be ascertained by use only, and
not by appearance.

But Mr. Hennah, who has had much practical experience, recommends the
collodion to be made sensitive merely by the iodide of potassium; and he
said, "if it did not work quite clearly and well, a little tincture of
iodine brought it right." Here, then, is added the very thing which MR.
CROOKES proposes to abstract.

Again, MR. CROOKES considers the free iodine to be the cause of the
colouring of the collodion; will he then kindly explain its _modus
operandi_?

As he has on several occasions given your readers the benefit of his great
chemical knowledge, I trust they may be favoured by him with a solution of
these difficulties, which have puzzled

AN AMATEUR.

* * * * *

Replies to Minor Queries.

_Admissions to Inns of Court_ (Vol. viii., p. 540.).--The following
particulars may be of service to your correspondent who requires
information upon the subject of the matriculations at the inns of court.

The books of Lincoln's Inn, which record the calls to the bar and other
proceedings of the Society, commence in the second year of the reign of
Henry VI., 1423. Those of the Inner Temple, which contain the admittances
in 1547, and the calls to the bar in 1590; of the Middle Temple, which
contain a regular series of admissions and calls, about the year 1600; and
of Gray's Inn, about the year 1650. The earlier records of Gray's Inn were
destroyed by fire, but the Harleian MS. No. 1912., in the British Museum,
contains:

An alphabetical list of gentlemen admitted to that society, with the dates
of their admission, from 1521 to 1674.

Table of the admittances into Gray's Inn, declaring the names of the
gentlemen, the town and country whence they came, and the day, month, and
year when admitted, from the year 1626 to 1677.

Arms and names of noblemen and knights admitted to the said society.

An