ee petaemnsei
arises
-§0plot, exemplified by bird
fore fe linear on 4 semi-log
231 | mentioned in the section
moid conte ining predominantly
mirds.
Among the 28 plates counted most often (10 - 73 times) and
existence
Fmed to be counted frequently enough to detect the
f
linear semi-log relationship, only one other sample was
nearly linear by semi-log than by log-log plot.
This was
fgastric mill of a crab, Grapsus grapsus, taken March 26,
Ba, at Kabelle.
The graph (Figure 11) was sufficiently curved
. r indtoate the presence of more than one isotope.
The early
betion 50 - 300 days gave 4 half-life of 78 days, and the
tion 300 - 430 days gave a half-life of 107 days.
:
A section of
curve of another sample, muscle of sea cucumber (Figure 11),
8 typical of semi-log linearity.
The radioactivity of this
imple decayed over the period from 50 to nearly 200 days with
lf-life of about 75 days, but more slowly later.
;
Although a single isotope displays a downwardly concave
4 linear plot by log-log presentation, a mixture of as few
two isotopes with half-lives of similar orders of magnitude,
oh as Celtt and Cel44 of 30- and 280- day half-lives, may
; Sr almost linear on a log-log plot over the period of
Fto 500 days.
Most decays were best suited to log-log plotting as seen
} the seven examples in Figures 12 and 13.
Although some appear
tentiy curved, straight lines were fitted and slopes were
led graphically.
Definition of the curves requires evaluation not
only of
Y
*
ay