TRANSACTIONS OF THE SECTIONS. 148 
of Andral and Gavarret, and of Scharling, and explained the particulars in which he 
regarded them as defective for physiological inquiries. He then described the appa- 
ratus and method which he had devised for the prosecution of his researches, and 
which he considered to supply some of the deficiencies which he has pointed out. 
It enabled the author to absorb the whole of the carbonic acid from any volume of 
expired air, however large or small, during the period of expiration, and to measure 
the inspired air for any period, however long or short. All the air admitted was 
inspired and none was respired twice; and it was applicable to experiments with 
the body at rest, or in active exertion, and during sleep or wakefulness. 
The spirometer is a small dry gas meter of improved manufacture and registra- 
tion, and moves with an inverted action. It was connected with a mask, which was 
just large enough to cover the nose, mouth and chin, and had valves suitably 
arranged to prevent a retrograde current, and to direct the expired air into the ana- 
lytical apparatus. ‘The analytical apparatus consisted of a ‘‘ potass box,”’ made 
of gutta percha, and divided into chambers and cells; so that a column of air of 
2 in. X4 in. was directed over 700 superficial inches of a strong solution of caustic 
potass, and remained in so close and prolonged contact with it as to be entirely 
absorbed during each expiration, There were the usual desiccators of sulphuric 
acid of large capacity, and the balances employed weighed to the z}pth of a grain 
with 7lbs. in each pan. 
MicroscoricaL APPARATUS. 
Mr. C. Brooxz exhibited a microscope and case very completely fitted up, but 
having a stand of so simple and light a character as to render it very portable and 
convenient for use in the open air, at the seaside or elsewhere. It has a new and 
simple contrivance for the fine adjustment, and also for the rectangular adjustment 
of the secondary stage. A tourmaline inserted in one of the holes in the revolving 
diaphragm of a Powell’s condenser, permits the use of polarized light, without any 
change of illuminating apparatus. 
Mr. Brooke’s instrument was fitted with a double lens, so that the power could 
be changed from a high to a low one without unscrewing the glass. 
Mr. Lapp exhibited a microscope with an improved magnetic stage. The adjust- 
ments are effected by means of a steel chain; a moveable lever attached to the milled 
head gives a very efficient fine adjustment ; and the facility of moving objects deli- 
cately by the hand afforded by the magnetic stage was remarked upon as a great 
advantage. 
Mr. Wartneron described some additions which he had made to his portable 
microscope, by which living objects, as Polyzoa, &c., contained in glass bottles or 
small aquaria, could be examined with greater ease, over lengthened periods of time, 
and without disturbing them from their naturalized position. 
GEOGRAPHY AND ETHNOLOGY, 
The business of the Section was opened by Sir RopERick Murcuison, 
the President of the Section, in these words :— 
Lapies and Genrtemen,—Let me first congratulate our old members and adherents 
who are present upon having once more assembled in the great and flourishing 
county in which this Association had its origin. Twenty-seven years have elapsed 
since a small band of men, of whom I was one, met together in the city of York to 
establish the British Association for the Advancement of Science, and I rejoice to s 
that it was under the presidency of a virtuous and patriotic nobleman, the justly 
