CLINICAL
SIGNIFICANCE
OF
ADSORPTION
PHENOMENA.
'Oliver C. M. Davis, M.D. Bristol.
^ectiirey in Chemistry anfl Materia Medica in to
Out-Patients,
Bristol
University of Bristol ; Physician Royal Hospital for Sick Children and Women.
of the
present paper is to show that many of the Actions which take place in the body during disease exhibit cWacteristics which are closely parallel to the phenomena ^hich. have been grouped together under the designation of ^sorption or sorption. The phenomena of adsorption have given rise to much ^scussion during the past century, and a vast amount of ^Search has been carried out with the object of throwing object
%ht
upon the mechanisms involved. A few general remarks will first be made with reference to
hese phenomena
^scussion, Clted
and
as
the action of
iodine
before
entering into a more specialised typical example of adsorption may be various types of carbon upon solutions
a
in different solvents.
colour
Under favourable conditions
of the iodine solution diminishes in
Immediately this
the solid carbon is
intensity
into contact with
brought
solution.
Various
theories have been
brought
forward
as
to the
^Ure of this action. Freundlich,1 on the one hand, ?arded the phenomenon as exclusively a condensation on the
^face, whereas Travers considered that adsorption consists CJUsively of a more or less complete absorption into 2
ev
,
*
^
"
"
e
'
,
interior
of the solid.
A series of Writer
^e here. 205
experiments
on
adsorption
was
years ago,3 and will be The investigation consisted of some
carried out
briefly long
a
by
referred series of
206
OLIVER
DR.
It
on
was
DAVIS
the action of various
experiments demonstrating carbon
C. M.
types
of
standard solutions of iodine in different solvents.
clearly
panied by
"
adsorption
rapid
the surface there is
on
"
may be accoiH' and that in addition to a
absorption,"
condensation
"
shown that
a
slow diffusion
inwards
which goes on for long periods of time.* At the time of these experiments certain of the tubes
containing carbon, solvent,
hermetically sealed up intervening matters prevented
and iodine
left over, and various
were
the work
continued till
being
recently,
and their contents examined under the
opened
of Professor
prolonged period "
is the
a
100 c.c.
the carbon
by
"
original
of the solvent ;
weight of solution; "x/m"
m
of
is the
amount of iodine "
"
15 1 2
5 24 5 24 11
? ..
..
?
30
..
?
hour hours ?
?
days ?
years
by
x
.
.
.
o.
..
..
..
..
..
..
..
..
..
of
Iodine dissolved in Toluene?
229 0.237 0.245
.
..
265
293 0.299 0.315 0.327
0.3.79 0.509 "
*
100
gramme of carbon.
/m.
o.
.
one
o.
..
..
with
a?x o.
..
..
??
??
..
..
..
.
.
o.
.
.
..
o.
??
??
..
..
..
..
??
??
..
..
"
809
0-793 0.777
736 682
0-669 0.637 0.613 ?-5?9 0.250
McBain4 has introduced the term sorption as a generic and hypothetical term for the two phenomena here mentioned, which frequeI1 occur
together.
>
c.c-
therefore indicates the number
Animal Carbon
Time 5 minutes
gramineS
with the carbon
shaking (2 gm.) shaken
carbon
111
(1.2685 gm.)
is the number of
a?x
grammes of iodine sorbed
Sorption by
during the
of time.
of iodine left in solution after "
gradually increas-
well illustrates the
amounts of iodine taken up "
supervision
W. McBain.5
James following table
The
ing
when the tubes were
CLINICAL SIGNIFICANCE OF ADSORPTION PHENOMENA.
After eleven years there
hydriodic tion in
acid
was
in the tube,
present
2QJ
faintest trace of
only the showing
that the diminu-
concentration of the iodine solution cannot be ascribed
chemical action between solvent and solute.
The
next table shows similar results in the case of iodine
dissolved
in benzene
:?
Time. .
3
days
10
24 11
..
?
..
..
?
..
..
..
..
years
/m. 0.328
a?x.
x
..
0.33Q
0.386 0.561
..
..
..
..
..
..
..
..
Another important result of this research
strate conclusively
Spending by ^
here
on
that
0.589 0.495
0.146
grammes Carbon to
specific
a
Carbon
solution
c.c.
Time,
Animal Carbon
action
This is shown
:?
100
Cocoanut Carbon
demon-
was to
the nature of the carbon.
the following table
Sugar
is
adsorption
0.611
of
Iodine in Toluene.
x/m.
days.
3
..
..
..
..
o.
062
..
..
..
..
o.
299
.:
..
..
..
o.
329
It is especially important to recognise two essential differer*ces between chemical reactions and adsorption phenomena.
^ chemical ls
reactions the
directly proportional
Sut>stances, ^Weas in the Action occurs
position
to the
of
equilibrium set up concentrations of the reacting an
and in dilute solution reaction becomes slower, case
with
of
adsorption a nearly quantitative very low concentrations, and such
Quantitative adsorption The
is instantaneous.
result of these two factors is that
Clfculating
in extreme
^sorbed by specialised
Clrculating fluid,
and be
dilution cells
might
coming
deposited
on
be
a
substance
quantitatively
in contact with the
these cells in
a state
of
208
DR.
comparatively high cance
concentration.
DAVIS
This is of
special signifi-
layer of adsorbed material deep may alter all the properties of the solid
when it is remembered that
only one molecule so
OLIVER C. M.
a
covered.6
Experience of that vast field of chemical reaction known catalysis has demonstrated that these adsorption layers are the seat of enormously enhanced chemical reactivityas
Thus in many important industrial reactions, such as the manufacture of sulphuric acid from sulphur dioxide arid the contact process, it has been shown that the reaction, otherwise perhaps undetectable, is instantaneous oxygen
on
by
the surface of the proper catalyst. This is doubtless due to the very high local concentration
of the
reacting substances,
exposed of the
which at the
same
time
surrounding
fully affinity
are
to the effects of the chemical and residual
material.
these, coupled with the results of the adsorption experiments with iodine, have led the writer Such considerations
as
to believe that there is
phenomena
connection between
and certain
of Moore and these workers thetics
a
Roaf7
pathological gives support
made
laboratory experiments
brain
processes. to this
and
tissue, etc., upon anaesthetics form unstable compounds the
proteids paralysis of
of the tissue
cells,
The
work
belief,
since
with anaes-
that aggregates with
concluded or
the chemical activities of the
subject
is
"
and that anaesthesia is due to
result of the formation of such The
adsorption
protoplasm aggregations."
extremely complex,
and
as
a
as a
the tox*c
yet been isolated in a pure condition, satisfactory experiments with them have been impossible up to the present. It must* however, be pointed out in such cases that unless investigator5 substances which will be referred to have not
commence
must of
their research with
necessity
be
as
working hypothesis, progress extremely slow. It is obvious that a
CLINICAL SIGNIFICANCE OF ADSORPTION PHENOMENA.
in vitro
experiments with animals
replace practical experiments observations, but can only be used
can never
clinical
or
209
to support evidence obtained from other sources. We are undoubtedly justified in carrying out
experiments and
which
can
be
estimated
are
endeavouring to draw conclusions from support or controvert various theories
and in
accuracy,
laboratory readily adsorbed, quantitatively with great
with substances which
such results which
'With regard
to the
mechanism of
For this
reason
the
pharmacological action. experiments with carbon and iodine
above described would appear to be of great value. In the Writer's opinion there is clinical evidence to show that at any rate
one
of the earlier factors concerned in the action of
certain toxins is
adsorptive action. It would not be profitable at this stage of our knowledge to mention any considerable number of such probable cases, but a few will be noted. In the first place, those who have clinical experience with children are well aware of the alarming symptoms which may rapidly follow intestinal stasis, namely pain, drowsiness even approaching coma, and pyrexia or hyperpyrexia. In the majority of cases the administration of a mercurial purge Modifies all the symptoms within a few hours. The symptoms point to a temporary alteration in the function of Certain cerebral cells, and a feasible explanation is that this ls due to the action of an alimentary toxin. That this t?xin is chemically combined with the nervous tissue seems highly improbable, since the symptoms are so rapidly Modified by drugs which presumably act by indirectly "
reducing the by cutting off evacuation *-he
of
active
its
"
mass
source
of
decomposing
and accumulation of the toxin
supply,
i.e.
That the toxin is adsorbed by the active
chemical
period
action.
is
a
far
In the
more
days 16
?L- XXXVII. No. 141.
by bringing
about
an
material from the bowel. nervous
tenable
tissue
during
theory than that of
before the science of surgery
CLINICAL SIGNIFICANCE OF ADSORPTION
210
had reached its
present stage
PHENOMENA.
lardaceous disease
amyloid
or
present. Here we presumably have small quantities of a toxin slowly but progressively poured out into the tissues, finally producing definite chemical changes in the cell units. By active treatment these degenerations may be prevented in the early stages, quite probably because purely chemical change is preceded by adsorption phenomena, ,at which stage appropriate treatment has a chance of removing the toxin and
degeneration
its
stopping
was
far
than at
more common
Still
production.
the late cerebral lesions of
more
striking
is the
Here it may be
syphilis.
case
of
assumed
Treponema pallidum in minute quantities is adsorbed by the cerebral tissues, and if not removed during early stages finally brings about histological changes in the cells. There is one other type of disease in which the writer ventures to suggest that the phenomena of adsorption may be the main cause of the observed symptoms, namely the that the toxin thrown out
"
so-called "
"
"
and
unsatisfactory, properties of the
organic
it is
as
"
is
quite
becoming
obvious
constituent cells of the
modified without
foundly
histological change, of properties being a
diseases.
nervous
time the classification of diseases into
present
functional
Such
"
functional
At the
by
the
the an
giving rise to only evidence of
be
The fact of great
physical
may be
proany demonstrable such modification
body
observable disturbance in function-
physical properties of cells could brought about by an adsorption of toxins. that adsorption is a specific action appears to he
importance
if
we assume
case
of
in the
adsorption case
drugs or toxin5 by specialised tissuesthe two factors observed
that certain
undergo adsorption previously It is further suggested here that as
present
that the
and more
modification of the
certainly
in the
more
stated
of iodine
of toxin action.
he
by carbon may also A simple adsorption "
211
TUBERCULOSIS AND CONSUMPTION.
or
explain the rapid action alimentary canal. generated
surface condensation would
such toxins
as
those
not removed these
"
in the
"
adsorbed
of If
substances would doubtless
"
be slowly and progressively absorbed," finally bringing about dire results, as in the case of lardaceous disease and
syphilis previously
referred to.
To summarise, it is here
suggested that the action of toxins may take place in several stages, the first stage consisting of a condensation on the surface of specialised cells by adsorptive action. In this concentrated condition the toxins would exert a profound influence on the activities of the cells, and if not removed the second stage of diffusion inwards would be attained, accompanied or succeeded by definite chemical reactions bringing about histological
changes.
REFERENCES.
Freundlich, Habilitationschrift, Leipzig, 1906. " Travers, Adsorption and Occlusion," Proc. Roy. Soc., 1906. " The Adsorption of Iodine by Carbon," Trans. O. C. M. Davis, 3. Chem. Soc., 1907. 4. J. W. McBain. Zeit. physik. Chem., 1909, " 5Sorption of Iodine by Carbon," Trans. Faraday J- W. McBain, 1.
2.
Soc.,
6.
Soc.t 7.
1919.
Langmuir,
"
Adsorption of
Gases on Plane
Surfaces," J.
Am. Chem.
1918. "
The Physical and Chemical Moore and Roaf, of Chloroform," Proc. Roy. Soc., 1905.
Solutions
Properties
of
SIGNIFICANCE
OF
ADSORPTION
PHENOMENA.
'Oliver C. M. Davis, M.D. Bristol.
^ectiirey in Chemistry anfl Materia Medica in to
Out-Patients,
Bristol
University of Bristol ; Physician Royal Hospital for Sick Children and Women.
of the
present paper is to show that many of the Actions which take place in the body during disease exhibit cWacteristics which are closely parallel to the phenomena ^hich. have been grouped together under the designation of ^sorption or sorption. The phenomena of adsorption have given rise to much ^scussion during the past century, and a vast amount of ^Search has been carried out with the object of throwing object
%ht
upon the mechanisms involved. A few general remarks will first be made with reference to
hese phenomena
^scussion, Clted
and
as
the action of
iodine
before
entering into a more specialised typical example of adsorption may be various types of carbon upon solutions
a
in different solvents.
colour
Under favourable conditions
of the iodine solution diminishes in
Immediately this
the solid carbon is
intensity
into contact with
brought
solution.
Various
theories have been
brought
forward
as
to the
^Ure of this action. Freundlich,1 on the one hand, ?arded the phenomenon as exclusively a condensation on the
^face, whereas Travers considered that adsorption consists CJUsively of a more or less complete absorption into 2
ev
,
*
^
"
"
e
'
,
interior
of the solid.
A series of Writer
^e here. 205
experiments
on
adsorption
was
years ago,3 and will be The investigation consisted of some
carried out
briefly long
a
by
referred series of
206
OLIVER
DR.
It
on
was
DAVIS
the action of various
experiments demonstrating carbon
C. M.
types
of
standard solutions of iodine in different solvents.
clearly
panied by
"
adsorption
rapid
the surface there is
on
"
may be accoiH' and that in addition to a
absorption,"
condensation
"
shown that
a
slow diffusion
inwards
which goes on for long periods of time.* At the time of these experiments certain of the tubes
containing carbon, solvent,
hermetically sealed up intervening matters prevented
and iodine
left over, and various
were
the work
continued till
being
recently,
and their contents examined under the
opened
of Professor
prolonged period "
is the
a
100 c.c.
the carbon
by
"
original
of the solvent ;
weight of solution; "x/m"
m
of
is the
amount of iodine "
"
15 1 2
5 24 5 24 11
? ..
..
?
30
..
?
hour hours ?
?
days ?
years
by
x
.
.
.
o.
..
..
..
..
..
..
..
..
..
of
Iodine dissolved in Toluene?
229 0.237 0.245
.
..
265
293 0.299 0.315 0.327
0.3.79 0.509 "
*
100
gramme of carbon.
/m.
o.
.
one
o.
..
..
with
a?x o.
..
..
??
??
..
..
..
.
.
o.
.
.
..
o.
??
??
..
..
..
..
??
??
..
..
"
809
0-793 0.777
736 682
0-669 0.637 0.613 ?-5?9 0.250
McBain4 has introduced the term sorption as a generic and hypothetical term for the two phenomena here mentioned, which frequeI1 occur
together.
>
c.c-
therefore indicates the number
Animal Carbon
Time 5 minutes
gramineS
with the carbon
shaking (2 gm.) shaken
carbon
111
(1.2685 gm.)
is the number of
a?x
grammes of iodine sorbed
Sorption by
during the
of time.
of iodine left in solution after "
gradually increas-
well illustrates the
amounts of iodine taken up "
supervision
W. McBain.5
James following table
The
ing
when the tubes were
CLINICAL SIGNIFICANCE OF ADSORPTION PHENOMENA.
After eleven years there
hydriodic tion in
acid
was
in the tube,
present
2QJ
faintest trace of
only the showing
that the diminu-
concentration of the iodine solution cannot be ascribed
chemical action between solvent and solute.
The
next table shows similar results in the case of iodine
dissolved
in benzene
:?
Time. .
3
days
10
24 11
..
?
..
..
?
..
..
..
..
years
/m. 0.328
a?x.
x
..
0.33Q
0.386 0.561
..
..
..
..
..
..
..
..
Another important result of this research
strate conclusively
Spending by ^
here
on
that
0.589 0.495
0.146
grammes Carbon to
specific
a
Carbon
solution
c.c.
Time,
Animal Carbon
action
This is shown
:?
100
Cocoanut Carbon
demon-
was to
the nature of the carbon.
the following table
Sugar
is
adsorption
0.611
of
Iodine in Toluene.
x/m.
days.
3
..
..
..
..
o.
062
..
..
..
..
o.
299
.:
..
..
..
o.
329
It is especially important to recognise two essential differer*ces between chemical reactions and adsorption phenomena.
^ chemical ls
reactions the
directly proportional
Sut>stances, ^Weas in the Action occurs
position
to the
of
equilibrium set up concentrations of the reacting an
and in dilute solution reaction becomes slower, case
with
of
adsorption a nearly quantitative very low concentrations, and such
Quantitative adsorption The
is instantaneous.
result of these two factors is that
Clfculating
in extreme
^sorbed by specialised
Clrculating fluid,
and be
dilution cells
might
coming
deposited
on
be
a
substance
quantitatively
in contact with the
these cells in
a state
of
208
DR.
comparatively high cance
concentration.
DAVIS
This is of
special signifi-
layer of adsorbed material deep may alter all the properties of the solid
when it is remembered that
only one molecule so
OLIVER C. M.
a
covered.6
Experience of that vast field of chemical reaction known catalysis has demonstrated that these adsorption layers are the seat of enormously enhanced chemical reactivityas
Thus in many important industrial reactions, such as the manufacture of sulphuric acid from sulphur dioxide arid the contact process, it has been shown that the reaction, otherwise perhaps undetectable, is instantaneous oxygen
on
by
the surface of the proper catalyst. This is doubtless due to the very high local concentration
of the
reacting substances,
exposed of the
which at the
same
time
surrounding
fully affinity
are
to the effects of the chemical and residual
material.
these, coupled with the results of the adsorption experiments with iodine, have led the writer Such considerations
as
to believe that there is
phenomena
connection between
and certain
of Moore and these workers thetics
a
Roaf7
pathological gives support
made
laboratory experiments
brain
processes. to this
and
tissue, etc., upon anaesthetics form unstable compounds the
proteids paralysis of
of the tissue
cells,
The
work
belief,
since
with anaes-
that aggregates with
concluded or
the chemical activities of the
subject
is
"
and that anaesthesia is due to
result of the formation of such The
adsorption
protoplasm aggregations."
extremely complex,
and
as
a
as a
the tox*c
yet been isolated in a pure condition, satisfactory experiments with them have been impossible up to the present. It must* however, be pointed out in such cases that unless investigator5 substances which will be referred to have not
commence
must of
their research with
necessity
be
as
working hypothesis, progress extremely slow. It is obvious that a
CLINICAL SIGNIFICANCE OF ADSORPTION PHENOMENA.
in vitro
experiments with animals
replace practical experiments observations, but can only be used
can never
clinical
or
209
to support evidence obtained from other sources. We are undoubtedly justified in carrying out
experiments and
which
can
be
estimated
are
endeavouring to draw conclusions from support or controvert various theories
and in
accuracy,
laboratory readily adsorbed, quantitatively with great
with substances which
such results which
'With regard
to the
mechanism of
For this
reason
the
pharmacological action. experiments with carbon and iodine
above described would appear to be of great value. In the Writer's opinion there is clinical evidence to show that at any rate
one
of the earlier factors concerned in the action of
certain toxins is
adsorptive action. It would not be profitable at this stage of our knowledge to mention any considerable number of such probable cases, but a few will be noted. In the first place, those who have clinical experience with children are well aware of the alarming symptoms which may rapidly follow intestinal stasis, namely pain, drowsiness even approaching coma, and pyrexia or hyperpyrexia. In the majority of cases the administration of a mercurial purge Modifies all the symptoms within a few hours. The symptoms point to a temporary alteration in the function of Certain cerebral cells, and a feasible explanation is that this ls due to the action of an alimentary toxin. That this t?xin is chemically combined with the nervous tissue seems highly improbable, since the symptoms are so rapidly Modified by drugs which presumably act by indirectly "
reducing the by cutting off evacuation *-he
of
active
its
"
mass
source
of
decomposing
and accumulation of the toxin
supply,
i.e.
That the toxin is adsorbed by the active
chemical
period
action.
is
a
far
In the
more
days 16
?L- XXXVII. No. 141.
by bringing
about
an
material from the bowel. nervous
tenable
tissue
during
theory than that of
before the science of surgery
CLINICAL SIGNIFICANCE OF ADSORPTION
210
had reached its
present stage
PHENOMENA.
lardaceous disease
amyloid
or
present. Here we presumably have small quantities of a toxin slowly but progressively poured out into the tissues, finally producing definite chemical changes in the cell units. By active treatment these degenerations may be prevented in the early stages, quite probably because purely chemical change is preceded by adsorption phenomena, ,at which stage appropriate treatment has a chance of removing the toxin and
degeneration
its
stopping
was
far
than at
more common
Still
production.
the late cerebral lesions of
more
striking
is the
Here it may be
syphilis.
case
of
assumed
Treponema pallidum in minute quantities is adsorbed by the cerebral tissues, and if not removed during early stages finally brings about histological changes in the cells. There is one other type of disease in which the writer ventures to suggest that the phenomena of adsorption may be the main cause of the observed symptoms, namely the that the toxin thrown out
"
so-called "
"
"
and
unsatisfactory, properties of the
organic
it is
as
"
is
quite
becoming
obvious
constituent cells of the
modified without
foundly
histological change, of properties being a
diseases.
nervous
time the classification of diseases into
present
functional
Such
"
functional
At the
by
the
the an
giving rise to only evidence of
be
The fact of great
physical
may be
proany demonstrable such modification
body
observable disturbance in function-
physical properties of cells could brought about by an adsorption of toxins. that adsorption is a specific action appears to he
importance
if
we assume
case
of
in the
adsorption case
drugs or toxin5 by specialised tissuesthe two factors observed
that certain
undergo adsorption previously It is further suggested here that as
present
that the
and more
modification of the
certainly
in the
more
stated
of iodine
of toxin action.
he
by carbon may also A simple adsorption "
211
TUBERCULOSIS AND CONSUMPTION.
or
explain the rapid action alimentary canal. generated
surface condensation would
such toxins
as
those
not removed these
"
in the
"
adsorbed
of If
substances would doubtless
"
be slowly and progressively absorbed," finally bringing about dire results, as in the case of lardaceous disease and
syphilis previously
referred to.
To summarise, it is here
suggested that the action of toxins may take place in several stages, the first stage consisting of a condensation on the surface of specialised cells by adsorptive action. In this concentrated condition the toxins would exert a profound influence on the activities of the cells, and if not removed the second stage of diffusion inwards would be attained, accompanied or succeeded by definite chemical reactions bringing about histological
changes.
REFERENCES.
Freundlich, Habilitationschrift, Leipzig, 1906. " Travers, Adsorption and Occlusion," Proc. Roy. Soc., 1906. " The Adsorption of Iodine by Carbon," Trans. O. C. M. Davis, 3. Chem. Soc., 1907. 4. J. W. McBain. Zeit. physik. Chem., 1909, " 5Sorption of Iodine by Carbon," Trans. Faraday J- W. McBain, 1.
2.
Soc.,
6.
Soc.t 7.
1919.
Langmuir,
"
Adsorption of
Gases on Plane
Surfaces," J.
Am. Chem.
1918. "
The Physical and Chemical Moore and Roaf, of Chloroform," Proc. Roy. Soc., 1905.
Solutions
Properties
of
