98 
found between the amounts of forward and upward move- 
ments, and from the measurement of the angles made by 
the ribs with the spine it may be shown, that these angles 
are not such as to permit of the degree of forward motion 
recorded by the three-plane stethometer. 
In some instances the discrepancy between the observed 
and the calculated forward movement amounted to O’oin. 
for the fifth rib and 0‘7in. for the third rib. 
From these facts the conclusion has been drawn that in 
forced breathing the extreme effort of expiration causes a 
certain degree of inbending of the ribs. 
This explanation was further shown to be correct by the 
use of a pair of callipers, especially devised for measuring 
the diameters of the rib-circuits in the two positions of ex- 
treme inspiration and forced expiration. In the case exhi- 
bited to the Society the difference between the chordlength 
of the right third rib in expiration and inspiration was 
proved to be about 0'4in. 
Further confirmation of these views was found in the 
tracings of the stethograph, shown to the Society four weeks 
ago. 
Diagrams of these tracings, prepared by the Eev. Brooke 
Herford, were exhibited to the meeting. 
Mr. Carson desires to correct a statement which appears 
in a notice read at the meeting on January I8th last, “On 
a Crystalline Sublimed Cupric Chloride,” in which, through 
a misunderstanding, he stated that sodium chloride was 
volatilized in Deacon’s chlorine process when sodium sul- 
phate is added to the copper salt. He since has learnt from 
Mr. Deacon that no such volatilization of sodium chloride 
has been observed. 
