1872.] Chemical Science. 1 Be 
Mr. J. Parry has devised and carried out practically a new form of gas 
apparatus, which possesses advantages over those of Bunsen and Frankland 
and Ward. The measuring or gas tube, a, is enclosed in a glass cylinder 
filled with water, and dips into the mercury trough, B. The absorbing and 
eudiometer-tube, c, is connected with a by a well-fitting elastic tubing of 
double thickness, firmly wired to the capillary glass tubing shown in the sketch. 
The use of this apparatus hardly requires to be described. By alternately 
raising and lowering the mercury reservoir, R, both a and c are filled. The 
gas for analysis being then bubbled up 
into A, and measured with the usual pre- 
caution. The liquid absorbent required Fic. 8. 
is poured into the cup, G; R is lowered, i) 
M opened, thus drawing the test into c, a ©} 
little being left in the cup to prevent ad- 4 
mission of air. The tap,N, isnow opened, Ls) 
and the gas drawn into c; both M andN are 
to be kept closed while the gas is being 
subjected to the action of the absorbent. 
The latter must always berun into c as de- 
scribed, or it is drawn into the measuring- 
tube. Tocleanc the gas is passed back 
into A, N is closed, and m opened, B lowered, 
and the mercury and absorbent allowed to 
flow out to about the level of L (see 
dotted line). Unscrewing the nuts H and 
D, the lower part, w, is taken out, the test, 
&c., falling into a large basin placed under. 
While the mercury, &c., is falling down 
the tube, c, water must be poured into the 
cup, G, for washing out traces of the 
absorbent. The eudiometer-tube, c, is 
well washed with pure water, with the 
pipette, o (which consists only of an 
ordinary pipette joined to a long glass 
tube by a short piece of elastic tubing) ; 
it is evident the long tube may thus be conveniently passed up c, and the water 
blown through and up c, flowing down the sides of the tube into the basin. 
The part w is made of ironor steel of the form shown; a plug of caoutchouc 
is firmly cemented into the short iron tube; the platina wires for explosions 
insulated in glass tubing, also the glass tube (wired to the elastic tubing, F, by 
which the reservoir, R, is raised and lowered) are passed air-tight through the 
caoutchouc plug. The flanges, &c., w and L, should be well made with smooth 
true surfaces ; a washer of caoutchouc is placed between the flanges, also the 
end of c presses down on the plug when the nuts H and D are screwed down. 
By means of this apparatus analyses are rapidly and conveniently done; 
explosions are accomplished without difficulty, with far less trouble and risk 
than with the ordinary eudiometer; the gas for explosion may be expanded to 
any required extent by lowering R, and any risk of bursting c is thus entirely 
obviated. Water may be substituted for mercury in the trough, B, but of 
course, with less accurate results. The eudiometer, c, may be supported by 
clamps attached to a long iron rod, and R raised or lowered by a pulley. 
aul 
(SOs oes Se So 
Dugald Campbell, F.C.S., has recently analysed some ancient Jewish glass 
obtained from Bessant, secretary to the ‘‘ Palestine Exploration Fund,” and 
which, that gentlemen writes, ‘Is all from shafts round the Temple, and found 
at depths varying from 20 to 8o feet,” and as its history is truly interesting and 
its composition is somewhat curious, an analysis may not be out of place in 
the pages of this journal. The sample of glass weighed altogether about 
3 ounces, and consisted of a number of small pieces, many of which in parts 
had undergone a change both in structure and colour by time and exposure. 
The portion sele@ed for analysis was from pieces which appeared to have 
undergone the least if any change, and the results were as follows, in roo parts : — 
VOL. Il. (N.S.) Q 
