ON THE USE OF LEAD IN EUDIOMETRY. 
321 
M. Lowig has found, in hydrocyanic ether prepared with 
oxalic ether, properties analogous to those of the hydrocyanic 
ether of M. Pelouze. 
Journ. de Pharm. and Jlnndl. der Physik und Chemie. 
ART. LIL— ON THE USE OF LEAD IN EUDIOMETRY. 
By M. Theodore de Saussure. 
It is known that leaden shot, moistened with water, and 
agitated with common air, absorbs oxygen from the latter, at 
ordinary atmospheric temperatures. This property, which 
has not hitherto been applied to any useful purpose, affords a 
method by which the proportion of oxygen in the air may be 
determined within the one-thousandth part, and which in se- 
veral respects, may be found preferable to the eudiometers 
in common use. The process requires about three hours agi- 
tation for its completion. The vessel in which the operation 
is performed is a matras, or cucurbit, to the neck of which 
is cemented a metallic ring, with slopes fitted to receive a 
key. This ring contains a screw which extends rather less 
than two-tenths of an inch within the ring, and is adapted to 
a metallic plug with a square head, also fitted to receive a 
key. There is a flanch about one-fourth of an inch wide, pro- 
vided with a collar of leather, which is made to press the 
outer edge of the ring of the matras. The keys are designed 
to screw down firmly the plug, and to prevent the necessity 
of touching the matras during the operation. The matrases 
employed in my experiments on common air, have had a ca- 
pacity of from nine to twelve cubic inches. The neck was 
generally about six inches long, and its capacity from one- 
third to one-fourth that of the body or bulb of the instrument, 
in order to measure the absorption of atmospheric oxygen in 
this part of the matras. The glass ought not to be less than 
^ T of an inch in thickness, owing to the danger uf breaking 
by the agitation of the shot. The grains of shot should be the 
vol. ir — no. iv. 41 
