- Email: [email protected]
BLOOD IN THE STOOLS
688 in the degenerative forms. In the cases of polyarthritis due to rheumatic fever, pain rapidly diminished and there was progressive reduction in the articular swelling, the temperature, and the sedimentation-rate. This substance has also been tested on 5 cases of blood disease-2 of acute leukaemia, 1 of chronic myeloid leukæmia, and 2 of Hodgkin’s disease. In the cases of acute leukaemia it had no effect. In the case of chronic leukaemia, however, the result was encouraging : the size of the spleen diminished and peripheral leucocytes became fewer. The results were also hopeful in the two cases of Hodgkin’s disease, where the affected lymphglands became progressively smaller. The doses used varied from a maximum of 400 mg. (loading dose) to a minimum of 100 mg. (maintenance dose). The preparations used were always well tolerated ; there was no restlessness, insomnia, or change in the
virtually
blood-pressure or pulse-rate. No appreciable effecton carbohydrate and mineral metabolism has been observed. In the cases of arthropathy the circulating leucocytes gradually grew fewer and 5 relative lymphocytosis and eosinophilia was observed.4 Thus for the first time a substance of vegetable origin to which a formula of steroid nature has been ascribed, has been found clinically to have the same applications as the most potent steroids of animal origin. This discovery reveals a new field for biochemical research. GIORGIO FERRARI Institute of Pathology, ANNIBALE ALLEGRI. of Pavia. University BLOOD IN THE STOOLS
SIR,-Your annotation of March 18 touches an aspect of diagnosis in which the general practitioner can play an important part. It is to his own doctor that a patient first goes, and it should be almost axiomatic that when symptoms of alimentary upset do not clear up in a few days, or where the cause of an illness is obscure, particularly in patients past middle-age, the stool should be examined for occult blood. It is true, as you say, that tests for occult blood have in some quarters fallen into disrepute. That is not because most gastro-enterologists consider them unreliable, but because of the short cut to diagnosis by X-ray examination, and because of uncertainty about interpretation of positive findings. The test now pretty generally used in clinical laboratories is the benzidine test : it is perhaps the most sensitive of all, giving a positive result in blood diluted to 1 in 250,000 parts of water. For routine use in general practice, however, there are obvious objections to a test which gives positive results with gum-bleeding, and after the eating of meat in moderate amounts. It was to overcome such objections that Gregersen 6 introduced his slide test, universally known as the Gregersen slide test (G.s.T.). By reducing the sensitivity of the benzidine test to one-third, he produced what is now regarded as one of the most reliable tests for everyday clinical use. He discarded the unstable hydrogen peroxide and substituted the more stable barium peroxide in a concentration of 4%. Using a 50% aceticacid solution, the benzidine concentration is kept at 0.5%. The practical application of the test is thus standardised, and leaves no room for error. A powder containing 0-025 g. of benzidine and 0-2 g. of barium peroxide is dissolved in 5 ml. of 50% acetic acid. A portion of fœces, the size of a split pea, taken if possible from the interior of the specimen, is smeared on a clean glass slide ; In the presence of a few drops of the reagent are added. blood, a blue colour, varying in intensity with the amount of blood present, develops in less than a minute. Because different makes of reagent give varying results, it is advisable always to use the same make. the
meeting of the Società Lombarda di Scienze Mediche e Biologiche, Jan. 17, 1950. 5. Allegri, A. Minerva Med. 1950, 41, 246. 6. Gregersen, J. P. Ugeskr. Laeg. 1916, 78, 697, 752, 1197, 1260.
4.
Allegri,
A.
Report
on
The Gregersen slide test is fully described by Ha,rrison7 and by Hutchison and Hunter,8 and is widely used on the Continent and in America. Boas favoured it, and Ogilvie,’ concluded that a blue or a blue-green colour, appearing within 30 seconds, is positive proof of the presence of occult blood, irrespective of the patient’s diet, with the obvious exception of black pudding, liver, bone-marrow, and other foods with a high concentration of blood
pigment. the guaiac test favoured by Hoerr, the Gregersen slide test gives no false-positive results with iron, and it requires only two reagents instead of three. Further, the reagents are stable over a period of at least six months, whereas the guaiac solution has to be renewed after a month. It is surprising, therefore, to read in the report of a discussion following their paper, that Hoerr and his colleagues had no experience of this widely used test which has so well-established a place in the Unlike
textbooks.
I have used the Gregersen slide test in general practice for the past twenty years and have described 10 a series of 123 alimentary cases (including 102 cases of peptic ulcer) in which both X-ray and G.S.T. findings are
available. The G.S.T. findings were compared with the X-ray and clinical findings, including in some cases confirmation after operation. Both the G.s.T. and X-ray findings were positive in 69 (68%) of 102 ulcer cases, and in 18 (86%) of 21 other conditions. The G.S.T. was positive and the X-ray findings negative, but clinical observations and subsequent history confirmed the positive diagnosis, in 19 of the 102 ulcer cases and 3 of the 21 other cases. The G.S.T. was negative, and positive X-ray findings confirmed the clinical findings, in 14 of the 102 ulcer cases, but in none of the 21 other cases. Thus there were 22 cases which might have been missed if the G.S.T. had not been used, and 14 cases in which the G.S.T. did not support the diagnosis. In more than two-thirds of all cases both the G.s.T. and the X-ray findings were positive. Of these 87 cases, all but 22 were first diagnosed with the G.s.T. Where the two tests gave differing results, the G.S.T. was right rather more often than the X-ray findings (22 cases and 14 cases respectively). Of the 19 ulcer cases with initial negative X-ray findings, 3, radiographed again after an interval because of a persistently positive G.s.T., gave a positive result; and 2 cases, one of neoplasm and the other of diverticulitis, both of them with initial negative X-ray findings and re-examined for the same, reason, subsequently gave positive X-ray findings. These 5 cases are perhaps among the most significant in the series. As regards ulcer only, both tests agreed in two-thirds of the cases ; radiography failed in slightly under 1 case out of 5, and the G.s.T. in slightly less than 1 out of every 7 cases. For the other diagnoses the numbers are too small to give more than a strong indication: 11 cases of neoplasm ; 5 which exhibited diverticulosis radiologically and had a positive G.S.T. (presumably cases of diverticulitis) ; and 1 case each of ulcerative colitis, regional ileitis, torsion of the caecum, spastic colon, and pernicious anaemia.
For the general practitioner the G.S.T. can be a valuable aid to early diagnosis and treatment of ulcer. By its use he can sift and control his dyspepsias with more assurance and a better knowledge of the underlying pathology. Often it may enable him to decide more quickly which case requires the more expensive and timeconsuming forms of investigation. By taking appropriate measures until all occult blood has disappeared from the faeces, it may enable him to avert the more serious complications of haemorrhage and perforation. As the minimal amount of blood required to give a positive result varies from one person to another, a negative finding must not be considered conclusive and should always be judged in relation to the clinical picture. A positive result is always significant; and, 7. Harrison, G. A. Chemical Methods in Clinical Medicine. London, 1947. 8. Hutchison, R., Hunter, D. Clinical Methods. London, 1935, 9. Ogilvie, A. G. Brit. med. J. 1927, i, 755. 10. Lipetz, S. Lancet, 1948, ii, 587.
689 have been taken to exclude extraneous sources of blood, an attempt must always be made to trace the cause of the bleeding. Interpreted thus critically, these tests can be indeed valuable, as you suggest. If they were widely applied in general practice, alimentary disease would be more rapidly detected at a stage when treatment can be successfully instituted. S. LIPETZ. Edinburgh.
provided precautions
provision of facilities. If it is thought that expenditure on X-ray film is likely to become too great for the country to afford, it would, in my personal view, be cheaper in the long run to spend money on research into electronic methods of enhancing the brilliance of the X-ray screen image. If this could be done, there would be little need for radiography. The money spent in the eventual treatment of even a few minimal cases " missed " by chest fluoroscopy would take us far towards achieving this goal! J. ASPIN. Leeds. .
DIAGNOSTIC CHEST FLUOROSCOPY SIR,—In advocating the use of fluoroscopy rather than radiography in the search for pulmonary tuberculosis. Dr. Hall and Dr. Tattersall (March 18) are taking a retrograde step. No-one can deny that an X-ray film is more reliable than screening in the detection of a small pulmonary lesion, no matter how much skill and visual purple the fluoroscopist may possess. In addition, the X-ray film provides a permanent record which may be of very great value in. the future management of the
patient. Why then
should we use fluoroscopy in diagnosis when better method is available ?Dr. Hall and Dr. Tattersall give two reasons—ease and speed of examination, and cheapness. In your annotation on their article you quote an impressive body of evidence, covering some thousands of cases, to show that 13-35% of clinically significant lesions are missed when fluoroscopy alone is employed. I submit that, in the campaign against tuberculosis, we cannot afford such a sacrifice of reliability for the sake of speed and cheapness. The pioneer work of Toussaint and Pritchard in London has shown the value of cooperation between the chest clinic and the local practitioners when diagnostic radiography is available. The time has come for all tuberculosis workers to insist that every chest clinic must be provided with an X-ray plant and an adequate staff, so that a film may be taken of every patient who comes up for diagnosis. A screening apparatus is also essential in any clinic where pneumothorax refills are undertaken, but its use should be restricted to this work and to the study of movement. Surely our task is to press for an efficient service and not, as your annotation suggests, " to think of ways of lightening the load." A revival of the obsolescent practice of diagnostic fluoroscopy would be particularly unfortunate at the present time, since it might persuade those responsible for providing the equipment of chest can be clinics that a relatively inexpensive substituted for an X-ray plant. Brompton Hospital Sanatorium, A. F. FOSTER-CARTER. a
fluoroscope
Frimley, Aldershot, Hants.
SIR,—Dr. Hall and Dr. Tattersall are to be congratulated on their excellent exposition of the technique of chest fluoroscopy. But surely they go too far in suggesting that fluoroscopy should supplant, rather than supplement, radiography in diagnostic chest clinics. Practitioners referring cases to these clinics are entitled to receive a first-rate opinion based upon all relevant clinical, pathological, and radiological investigations. As far as radiology is concerned, the matter can be summarised by the
following equations : Radiography+ fluoroscopy Radiography alone Photofluoroscopy alone Fluoroscopy alone
or
=
Best
=
Next best
l-
’
Not goodenough. enough. f chest physicians have been urging practi-
For years, tioners to send up cases for examination and chest radiography on the slightest pretext. Now that this advice is meeting with an ever-growing response, we should not resort to second-rate methods just because the volume of work is growing faster than the present
SIR,—Dr. Hall and Dr. Tattersall
are to be co,ngratutheir most timely article of March 18, which amplifies Dr. Tattersall’s original account of the use of this method in the chest clinic. There is, unfortunately, still considerable opposition to the use of this diagnostic technique, on the grounds that fluoroscopy does not give as accurate results as does a full-size radiograph or even mass miniature radiography, and that both operator and patient are exposed to radiation risk. Having screened for diagnostic purposes more than 2900 patients during the last eleven months, I feel that, provided a careful technique is strictly adhered to, the results obtained are at least as good as those of miniature fluorophotography. Where no pulmograph is available, chest physicians should be encouraged to make greater use of fluoroscopy in the interests both of early diagnosis and of economy in time and materials. In our experience, several minimal apical lesions found on fluoroscopy could subsequently be identified either with difficulty or not at all on the conventional posteroanterior film, though these lesions might be demonstrable by special techniques such as the apical lordotic film. So far no patient found negative by us on fluoroscopy has subsequently been notified as tuberculous, so that it seems that no lesion of any size has been missed by this method. As Dr. Hall and Dr. Tattersall emphasise, fluoroscopy has the advantage of giving a dynamic, three-dimensional view of the lung fields, and of rendering visible obscure portions such as the posterior costophrenic sinuses, the upper and posterior mediastinum, the retrocardiac area, and the regions covered by the conjunction of first rib and clavicle. Although we are now screening at the rate of 100 patients a week, investigation by the National Physical Laboratory showed that neither physician nor radiographer was receiving as much as 0.05 rontgen of radiation in one-week. The British X-ray and Radium Protection Committee recommend that the dose should not exceed 0.5 rontgen per week. There is therefore no evidence that the method exposes the operator to any considerable risk. 3000 screenings in a year represent a notable saving both in the cost of materials and storage space and in the time of patients and staff. The ease with which a fluorography report can be obtained has encouraged practitioners to refer patients with minimal symptoms, and often only because of a bad family history or of a history of contact at work. In this way a higher proportion of early cases has been seen during the-past It is frequently objected that year than previously. fluoroscopy leaves no permanent record beyond the operator’s report. This is equally true of any other clinical examination except where results can be expressed in figures or by a mechanical tracing (e.g., weight, bloodcount, photograph, or electrocardiogram)-. In my view this objection is more than counterbalanced by the obvious economic advantages. The merits of diagnostic fluoroscopy must not, howIt is an incomplete ever, blind us to its limitations. method of examination, and a negative report does not exonerate the general practitioner from examining his patient and, if necessary, referring him for further advice. It is noteworthy that all too often patients are referred
lated
on
’
virtually
blood-pressure or pulse-rate. No appreciable effecton carbohydrate and mineral metabolism has been observed. In the cases of arthropathy the circulating leucocytes gradually grew fewer and 5 relative lymphocytosis and eosinophilia was observed.4 Thus for the first time a substance of vegetable origin to which a formula of steroid nature has been ascribed, has been found clinically to have the same applications as the most potent steroids of animal origin. This discovery reveals a new field for biochemical research. GIORGIO FERRARI Institute of Pathology, ANNIBALE ALLEGRI. of Pavia. University BLOOD IN THE STOOLS
SIR,-Your annotation of March 18 touches an aspect of diagnosis in which the general practitioner can play an important part. It is to his own doctor that a patient first goes, and it should be almost axiomatic that when symptoms of alimentary upset do not clear up in a few days, or where the cause of an illness is obscure, particularly in patients past middle-age, the stool should be examined for occult blood. It is true, as you say, that tests for occult blood have in some quarters fallen into disrepute. That is not because most gastro-enterologists consider them unreliable, but because of the short cut to diagnosis by X-ray examination, and because of uncertainty about interpretation of positive findings. The test now pretty generally used in clinical laboratories is the benzidine test : it is perhaps the most sensitive of all, giving a positive result in blood diluted to 1 in 250,000 parts of water. For routine use in general practice, however, there are obvious objections to a test which gives positive results with gum-bleeding, and after the eating of meat in moderate amounts. It was to overcome such objections that Gregersen 6 introduced his slide test, universally known as the Gregersen slide test (G.s.T.). By reducing the sensitivity of the benzidine test to one-third, he produced what is now regarded as one of the most reliable tests for everyday clinical use. He discarded the unstable hydrogen peroxide and substituted the more stable barium peroxide in a concentration of 4%. Using a 50% aceticacid solution, the benzidine concentration is kept at 0.5%. The practical application of the test is thus standardised, and leaves no room for error. A powder containing 0-025 g. of benzidine and 0-2 g. of barium peroxide is dissolved in 5 ml. of 50% acetic acid. A portion of fœces, the size of a split pea, taken if possible from the interior of the specimen, is smeared on a clean glass slide ; In the presence of a few drops of the reagent are added. blood, a blue colour, varying in intensity with the amount of blood present, develops in less than a minute. Because different makes of reagent give varying results, it is advisable always to use the same make. the
meeting of the Società Lombarda di Scienze Mediche e Biologiche, Jan. 17, 1950. 5. Allegri, A. Minerva Med. 1950, 41, 246. 6. Gregersen, J. P. Ugeskr. Laeg. 1916, 78, 697, 752, 1197, 1260.
4.
Allegri,
A.
Report
on
The Gregersen slide test is fully described by Ha,rrison7 and by Hutchison and Hunter,8 and is widely used on the Continent and in America. Boas favoured it, and Ogilvie,’ concluded that a blue or a blue-green colour, appearing within 30 seconds, is positive proof of the presence of occult blood, irrespective of the patient’s diet, with the obvious exception of black pudding, liver, bone-marrow, and other foods with a high concentration of blood
pigment. the guaiac test favoured by Hoerr, the Gregersen slide test gives no false-positive results with iron, and it requires only two reagents instead of three. Further, the reagents are stable over a period of at least six months, whereas the guaiac solution has to be renewed after a month. It is surprising, therefore, to read in the report of a discussion following their paper, that Hoerr and his colleagues had no experience of this widely used test which has so well-established a place in the Unlike
textbooks.
I have used the Gregersen slide test in general practice for the past twenty years and have described 10 a series of 123 alimentary cases (including 102 cases of peptic ulcer) in which both X-ray and G.S.T. findings are
available. The G.S.T. findings were compared with the X-ray and clinical findings, including in some cases confirmation after operation. Both the G.s.T. and X-ray findings were positive in 69 (68%) of 102 ulcer cases, and in 18 (86%) of 21 other conditions. The G.S.T. was positive and the X-ray findings negative, but clinical observations and subsequent history confirmed the positive diagnosis, in 19 of the 102 ulcer cases and 3 of the 21 other cases. The G.S.T. was negative, and positive X-ray findings confirmed the clinical findings, in 14 of the 102 ulcer cases, but in none of the 21 other cases. Thus there were 22 cases which might have been missed if the G.S.T. had not been used, and 14 cases in which the G.S.T. did not support the diagnosis. In more than two-thirds of all cases both the G.s.T. and the X-ray findings were positive. Of these 87 cases, all but 22 were first diagnosed with the G.s.T. Where the two tests gave differing results, the G.S.T. was right rather more often than the X-ray findings (22 cases and 14 cases respectively). Of the 19 ulcer cases with initial negative X-ray findings, 3, radiographed again after an interval because of a persistently positive G.s.T., gave a positive result; and 2 cases, one of neoplasm and the other of diverticulitis, both of them with initial negative X-ray findings and re-examined for the same, reason, subsequently gave positive X-ray findings. These 5 cases are perhaps among the most significant in the series. As regards ulcer only, both tests agreed in two-thirds of the cases ; radiography failed in slightly under 1 case out of 5, and the G.s.T. in slightly less than 1 out of every 7 cases. For the other diagnoses the numbers are too small to give more than a strong indication: 11 cases of neoplasm ; 5 which exhibited diverticulosis radiologically and had a positive G.S.T. (presumably cases of diverticulitis) ; and 1 case each of ulcerative colitis, regional ileitis, torsion of the caecum, spastic colon, and pernicious anaemia.
For the general practitioner the G.S.T. can be a valuable aid to early diagnosis and treatment of ulcer. By its use he can sift and control his dyspepsias with more assurance and a better knowledge of the underlying pathology. Often it may enable him to decide more quickly which case requires the more expensive and timeconsuming forms of investigation. By taking appropriate measures until all occult blood has disappeared from the faeces, it may enable him to avert the more serious complications of haemorrhage and perforation. As the minimal amount of blood required to give a positive result varies from one person to another, a negative finding must not be considered conclusive and should always be judged in relation to the clinical picture. A positive result is always significant; and, 7. Harrison, G. A. Chemical Methods in Clinical Medicine. London, 1947. 8. Hutchison, R., Hunter, D. Clinical Methods. London, 1935, 9. Ogilvie, A. G. Brit. med. J. 1927, i, 755. 10. Lipetz, S. Lancet, 1948, ii, 587.
689 have been taken to exclude extraneous sources of blood, an attempt must always be made to trace the cause of the bleeding. Interpreted thus critically, these tests can be indeed valuable, as you suggest. If they were widely applied in general practice, alimentary disease would be more rapidly detected at a stage when treatment can be successfully instituted. S. LIPETZ. Edinburgh.
provided precautions
provision of facilities. If it is thought that expenditure on X-ray film is likely to become too great for the country to afford, it would, in my personal view, be cheaper in the long run to spend money on research into electronic methods of enhancing the brilliance of the X-ray screen image. If this could be done, there would be little need for radiography. The money spent in the eventual treatment of even a few minimal cases " missed " by chest fluoroscopy would take us far towards achieving this goal! J. ASPIN. Leeds. .
DIAGNOSTIC CHEST FLUOROSCOPY SIR,—In advocating the use of fluoroscopy rather than radiography in the search for pulmonary tuberculosis. Dr. Hall and Dr. Tattersall (March 18) are taking a retrograde step. No-one can deny that an X-ray film is more reliable than screening in the detection of a small pulmonary lesion, no matter how much skill and visual purple the fluoroscopist may possess. In addition, the X-ray film provides a permanent record which may be of very great value in. the future management of the
patient. Why then
should we use fluoroscopy in diagnosis when better method is available ?Dr. Hall and Dr. Tattersall give two reasons—ease and speed of examination, and cheapness. In your annotation on their article you quote an impressive body of evidence, covering some thousands of cases, to show that 13-35% of clinically significant lesions are missed when fluoroscopy alone is employed. I submit that, in the campaign against tuberculosis, we cannot afford such a sacrifice of reliability for the sake of speed and cheapness. The pioneer work of Toussaint and Pritchard in London has shown the value of cooperation between the chest clinic and the local practitioners when diagnostic radiography is available. The time has come for all tuberculosis workers to insist that every chest clinic must be provided with an X-ray plant and an adequate staff, so that a film may be taken of every patient who comes up for diagnosis. A screening apparatus is also essential in any clinic where pneumothorax refills are undertaken, but its use should be restricted to this work and to the study of movement. Surely our task is to press for an efficient service and not, as your annotation suggests, " to think of ways of lightening the load." A revival of the obsolescent practice of diagnostic fluoroscopy would be particularly unfortunate at the present time, since it might persuade those responsible for providing the equipment of chest can be clinics that a relatively inexpensive substituted for an X-ray plant. Brompton Hospital Sanatorium, A. F. FOSTER-CARTER. a
fluoroscope
Frimley, Aldershot, Hants.
SIR,—Dr. Hall and Dr. Tattersall are to be congratulated on their excellent exposition of the technique of chest fluoroscopy. But surely they go too far in suggesting that fluoroscopy should supplant, rather than supplement, radiography in diagnostic chest clinics. Practitioners referring cases to these clinics are entitled to receive a first-rate opinion based upon all relevant clinical, pathological, and radiological investigations. As far as radiology is concerned, the matter can be summarised by the
following equations : Radiography+ fluoroscopy Radiography alone Photofluoroscopy alone Fluoroscopy alone
or
=
Best
=
Next best
l-
’
Not goodenough. enough. f chest physicians have been urging practi-
For years, tioners to send up cases for examination and chest radiography on the slightest pretext. Now that this advice is meeting with an ever-growing response, we should not resort to second-rate methods just because the volume of work is growing faster than the present
SIR,—Dr. Hall and Dr. Tattersall
are to be co,ngratutheir most timely article of March 18, which amplifies Dr. Tattersall’s original account of the use of this method in the chest clinic. There is, unfortunately, still considerable opposition to the use of this diagnostic technique, on the grounds that fluoroscopy does not give as accurate results as does a full-size radiograph or even mass miniature radiography, and that both operator and patient are exposed to radiation risk. Having screened for diagnostic purposes more than 2900 patients during the last eleven months, I feel that, provided a careful technique is strictly adhered to, the results obtained are at least as good as those of miniature fluorophotography. Where no pulmograph is available, chest physicians should be encouraged to make greater use of fluoroscopy in the interests both of early diagnosis and of economy in time and materials. In our experience, several minimal apical lesions found on fluoroscopy could subsequently be identified either with difficulty or not at all on the conventional posteroanterior film, though these lesions might be demonstrable by special techniques such as the apical lordotic film. So far no patient found negative by us on fluoroscopy has subsequently been notified as tuberculous, so that it seems that no lesion of any size has been missed by this method. As Dr. Hall and Dr. Tattersall emphasise, fluoroscopy has the advantage of giving a dynamic, three-dimensional view of the lung fields, and of rendering visible obscure portions such as the posterior costophrenic sinuses, the upper and posterior mediastinum, the retrocardiac area, and the regions covered by the conjunction of first rib and clavicle. Although we are now screening at the rate of 100 patients a week, investigation by the National Physical Laboratory showed that neither physician nor radiographer was receiving as much as 0.05 rontgen of radiation in one-week. The British X-ray and Radium Protection Committee recommend that the dose should not exceed 0.5 rontgen per week. There is therefore no evidence that the method exposes the operator to any considerable risk. 3000 screenings in a year represent a notable saving both in the cost of materials and storage space and in the time of patients and staff. The ease with which a fluorography report can be obtained has encouraged practitioners to refer patients with minimal symptoms, and often only because of a bad family history or of a history of contact at work. In this way a higher proportion of early cases has been seen during the-past It is frequently objected that year than previously. fluoroscopy leaves no permanent record beyond the operator’s report. This is equally true of any other clinical examination except where results can be expressed in figures or by a mechanical tracing (e.g., weight, bloodcount, photograph, or electrocardiogram)-. In my view this objection is more than counterbalanced by the obvious economic advantages. The merits of diagnostic fluoroscopy must not, howIt is an incomplete ever, blind us to its limitations. method of examination, and a negative report does not exonerate the general practitioner from examining his patient and, if necessary, referring him for further advice. It is noteworthy that all too often patients are referred
lated
on
’