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Report of Tests Made on Samples Submitted by
Dr. Flinn, July 27, 1925.
Preliminary examination of the specimens inficated that the
samples marked 1, 2, 3, and B, all in brown bottles, were suffic-
iently radio active for gamma ray measurements. Samples were
therefore hermetically sealed in a standard type of tube and
allowed to tand for about five weeks, afetr which a series of
readings were made
Sample 1, brown bottle, contains the equivalent of approximately
1.55 micro grams of radium element per garm.
Sample 2, brown bottle, con ains the equivalent of approximately
1.75 micro grams of redium element per nm.
Sample 3, brown bottle, contains the equivalent of approximately
0.02 micro grams of radium element per gram.
Sample B, brown bottle, contains the equivalent of approximately
0.23 micro grams of radium element per gram.
Inasmach as the quantity of radium or mesothorium in the remain-
ing samples, with the exception of the urine samples, is very
small it has been somewhat difficult to definitely establish
just what their activity amounted to in terms of radium element.
In some instances the activity is so small that it is quite
possible that the activatating agent was introduced by contam-
ination unless the operator who put the samples up used the
utmost of caution. It would have been a good idea had a sample
of some of the organs of an animal not reated with the zinc
sulphide been included, as that would have served as a check
for contamination, or the possibility of a slight ionizing power
that may be characteristic of the material as a result of the
method of treating.
Perhpas it will be advisable to describe in brief the method I
used in testing the following samples together with the data
obtained, as that may give a more concrete idea of the difficult-
ies involved in ascertaining the quantity of activating agant
contained per gram.
A specially constructed type of alpha ray electroscope was used.
First, the natural drift, that 18, the time required for the
quartz fibre in the electroscope to pass over a definite number
of divisions in the eyepiece, was determined withthe physical
conditions in the instrument the same as when the sample was to
be read. The sample was then introduced and the time required
Flinn report, page 2.
determined, for the quartz fibre to pass over the same divisions
as used in ascertaining the natural drift. It is obvious that
any change in the rate of movement of the fibre must be ascribed
to a change brought about by the ionization of the air within the
chamber, due to the presence of radioactive substances.
The natural dbift of the fibre over 10 divisions in the cases
listed below required 209 seconds.
Specimen 14, test tube, with material introduced required 192 sec.
Specimen 18,
11
11
11
V
11
=
195
11
Specimen 24,
"
11
19
11
"
#
202
"
Specimen 630,
#
11
11
"
"
H
203
=
Specimen K,
"
#
11
11
"
"
148
"
Specimen R,
11
11
19
11
"
=
197
11
Specimen W, brown bottle, "
11
"
#
147.5
"
Specimen Marrow, test tube,
If
11
"
193
=
When we consider that speciman B, which contains 0.23 micro grams
of radium element per gram causes the fibre to move over 10
divisions in 3 to 4 seconds we can realize that the quantity of
radium must be small in the above cases. I have made calculations
of the approximate quantity of radium slement or its equivalent
contained in the list of samples. It must be born in mind that
the values represent approximations only.
Specimen 14 contains the order of 5.0 X 10-4 10-4 micro 8 ra el per 8.
11
18
11
11
11
11
4.6
17
X
8 ra el per 8.
#
24
"
#
11
If
220
X
10-4
11
g ra el per 5.
11
630
"
11
11
11
2.0
x
10-4
11
g ra el per 8.
11
K
11
#
11
11
2.5
10-3
11
X
6 ra el per B.
11
R.
11
11
=
11
2.5
10-4
it
X
B ra el per B.
#
W
11
11
11
11
1.6
10-3
11
X
g ra el per B.
"
#
11
"
14
marrow
5.0
x
10-4
18
g ra el per 8.
I should ay that in all cases except K and W, where quite a
definite effect is recorded, the reaction is feeble. However,
there is no question but what we are justified in coming to the
conclusion that in all cas B the material is active. It may be
of interest to know that many inbeous igneous and sedimentary
rocks contain around 4 X 10-0 micro grams of radium element per
gram.
Considering the condition in which the specimens of urine were
received it was somewhat difficult to make very accurate radium
messurements. However, the specimens were all decidedly active.
Their content was of the order of 2.5 X 10 micrograms of r adium
element per gram. Specimen No.2 was the most active and specimen
No. 3 the least with No 1 falling intermediary.
H. H. Barker.
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"ocrText": "Report of Tests Made on Samples Submitted by\nDr. Flinn, July 27, 1925.\nPreliminary examination of the specimens inficated that the\nsamples marked 1, 2, 3, and B, all in brown bottles, were suffic-\niently radio active for gamma ray measurements. Samples were\ntherefore hermetically sealed in a standard type of tube and\nallowed to tand for about five weeks, afetr which a series of\nreadings were made\nSample 1, brown bottle, contains the equivalent of approximately\n1.55 micro grams of radium element per garm.\nSample 2, brown bottle, con ains the equivalent of approximately\n1.75 micro grams of redium element per nm.\nSample 3, brown bottle, contains the equivalent of approximately\n0.02 micro grams of radium element per gram.\nSample B, brown bottle, contains the equivalent of approximately\n0.23 micro grams of radium element per gram.\nInasmach as the quantity of radium or mesothorium in the remain-\ning samples, with the exception of the urine samples, is very\nsmall it has been somewhat difficult to definitely establish\njust what their activity amounted to in terms of radium element.\nIn some instances the activity is so small that it is quite\npossible that the activatating agent was introduced by contam-\nination unless the operator who put the samples up used the\nutmost of caution. It would have been a good idea had a sample\nof some of the organs of an animal not reated with the zinc\nsulphide been included, as that would have served as a check\nfor contamination, or the possibility of a slight ionizing power\nthat may be characteristic of the material as a result of the\nmethod of treating.\nPerhpas it will be advisable to describe in brief the method I\nused in testing the following samples together with the data\nobtained, as that may give a more concrete idea of the difficult-\nies involved in ascertaining the quantity of activating agant\ncontained per gram.\nA specially constructed type of alpha ray electroscope was used.\nFirst, the natural drift, that 18, the time required for the\nquartz fibre in the electroscope to pass over a definite number\nof divisions in the eyepiece, was determined withthe physical\nconditions in the instrument the same as when the sample was to\nbe read. The sample was then introduced and the time required\nFlinn report, page 2.\ndetermined, for the quartz fibre to pass over the same divisions\nas used in ascertaining the natural drift. It is obvious that\nany change in the rate of movement of the fibre must be ascribed\nto a change brought about by the ionization of the air within the\nchamber, due to the presence of radioactive substances.\nThe natural dbift of the fibre over 10 divisions in the cases\nlisted below required 209 seconds.\nSpecimen 14, test tube, with material introduced required 192 sec.\nSpecimen 18,\n11\n11\n11\nV\n11\n=\n195\n11\nSpecimen 24,\n\"\n11\n19\n11\n\"\n#\n202\n\"\nSpecimen 630,\n#\n11\n11\n\"\n\"\nH\n203\n=\nSpecimen K,\n\"\n#\n11\n11\n\"\n\"\n148\n\"\nSpecimen R,\n11\n11\n19\n11\n\"\n=\n197\n11\nSpecimen W, brown bottle, \"\n11\n\"\n#\n147.5\n\"\nSpecimen Marrow, test tube,\nIf\n11\n\"\n193\n=\nWhen we consider that speciman B, which contains 0.23 micro grams\nof radium element per gram causes the fibre to move over 10\ndivisions in 3 to 4 seconds we can realize that the quantity of\nradium must be small in the above cases. I have made calculations\nof the approximate quantity of radium slement or its equivalent\ncontained in the list of samples. It must be born in mind that\nthe values represent approximations only.\nSpecimen 14 contains the order of 5.0 X 10-4 10-4 micro 8 ra el per 8.\n11\n18\n11\n11\n11\n11\n4.6\n17\nX\n8 ra el per 8.\n#\n24\n\"\n#\n11\nIf\n220\nX\n10-4\n11\ng ra el per 5.\n11\n630\n\"\n11\n11\n11\n2.0\nx\n10-4\n11\ng ra el per 8.\n11\nK\n11\n#\n11\n11\n2.5\n10-3\n11\nX\n6 ra el per B.\n11\nR.\n11\n11\n=\n11\n2.5\n10-4\nit\nX\nB ra el per B.\n#\nW\n11\n11\n11\n11\n1.6\n10-3\n11\nX\ng ra el per B.\n\"\n#\n11\n\"\n14\nmarrow\n5.0\nx\n10-4\n18\ng ra el per 8.\nI should ay that in all cases except K and W, where quite a\ndefinite effect is recorded, the reaction is feeble. However,\nthere is no question but what we are justified in coming to the\nconclusion that in all cas B the material is active. It may be\nof interest to know that many inbeous igneous and sedimentary\nrocks contain around 4 X 10-0 micro grams of radium element per\ngram.\nConsidering the condition in which the specimens of urine were\nreceived it was somewhat difficult to make very accurate radium\nmessurements. However, the specimens were all decidedly active.\nTheir content was of the order of 2.5 X 10 micrograms of r adium\nelement per gram. Specimen No.2 was the most active and specimen\nNo. 3 the least with No 1 falling intermediary.\nH. H. Barker."
}