182. CW. Hinman—New Apparatus for Gas Analysis. 
nents; thus, the durations of the following combinations are 
placed after them in fractions of a second. 
Cyt Cu=s353 CstGs=si53 Cot B= 54; C3t+E3+G,—s25; 
~ C,+E,+G,+C,=;',th of a second. - 
The above mentioned facts suggest a curious physiological 
inquiry, viz: Does it require a combination of sounds, simple 
or composite, to remain on the ear the duration of an entire 
period, in order that it shall give the same sensation as is pro- 
duced when the same combination is sounded continuously? 
In other words, will a portion of the recurring composite vibra- 
tion produce the same sensation as an entire period or several 
periods? The solution of this problem has been the object of 
a pong ed experimental research, but up to this time the re- 
sults have been so difficult of interpretation that I have not 
arrived at any certain knowledge on the subject. I shall, how- 
ever, return to this interesting but very difficult work. — 
Art. XVII.— Description of a new Apparatus for Gas Analysis ; 
by C. W. Hinman. 
Some time since, haying occasion to make some analyses of 
illuminating gas, I read descriptions of several forms of appa- 
ratus for that purpose, but failed to find one which appeared 
quite satisfactory. 
n apparatus was desired which should be as far as possible 
free from fragile or costly parts, and which, without being too 
complicated, should require no corrections to be made for varia- 
tions in the pressure, temperature, or aqueous vapor; reliable 
results rather than minute accuracy being desired. eos 
e apparatus finally adopted operates on the same princi- 
ples as Williamson & Russell’s,* except that in my apparatus the 
gas is not exploded in the measuring tube, but in a bulb for 
that special purpose. The trough is nearly the same as that of 
Doyére,t aid pipettes are also used. 
he apparatus as made consists of a measuring tube a, about 
230 mm. long, about 20 mm. in diameter, divided into fortieths 
of an inch and calibrated with mercury as described by Bunsen. 
The tube is firmly held by a clamp on the end of the rod }, 
which rod slides up and down in ¢, and is clamped in any posl- 
tion by the screw d. A slow motion is given to c, and thus to 
the measuring tube, by means of the milled headed nut e, which 
works along a thread cut on the rod /, which is firmly secured 
iar Barrie eatin of Doyére’s Eudiomete: Ad. Wurtz Diction 
ides as Chere, I, p. 280, fig. 42.0” 
