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THE BALLISTOCARDIOGRAM
830 the rule ;
for the unwillingness may be transmitted to their detriment. (i) Movement of a bed or other furniture must never be avoided, for fear of giving trouble, if it is necessary to allow the examiner to take up a proper position. Great clinicians always put themselves in these postures by the light of nature ; but we are not all great clinicians ; and we need thought, and conscious attention to detail, in order to approach their standard of to her
patients,
inefficiency. London, W.1.
T. B. LAYTON.
INFECTION THROUGH SOAKED DRESSINGS SiR,--Sterile non-absorbent cotton-wool has many of the properties required by Dr. Colebrook and Mr. Hood (Oct. 30). A thick layer placed on the outside’of the absorbent cotton-wool dressing will keep the exterior of the burn dressing dry for a long time. Sterile ’nonabsorbent cotton-wool has been used as a bacterial air-filter for many years. I believe the U.S.A. shelldressing used to consist of a pad of absorbent cotton-wool backed by non-absorbent cotton-wool. The two layers were surrounded by gauze. J. A. MYERS. Bradford. ’
ACCIDENTAL INTRA-ARTERIAL INJECTION OF DRUGS to my SiB,—Mr. Cohen’s letter last week in reply criticism (Oct. 2) of his paper accuses me of " flaunting certain physiological facts," and misconstrues what I said. I did not suggest that the effects of the injections he describes were due to vasodilatation in the tissues or to trophic nervous activity, as he states I did ; nor did I make the ridiculous suggestion he attributes to me that thiopentone in the cases under consideration injected solely into a nerve without entering the was circulation. Obviously it did go into the circulation, but the very delay before the onset of unconsciousness, which Mr. Cohen pointed out is usual in these cases, indicates that the entry into the circulation is abnormal. All I suggested was that some of the injection irritated nerve-fibres. Mr. Cohen does not believe vasodilator fibres supply the skin, but how does he explain the effect of stimulation of the peripheral ends of the posterior nerve-roots and the axon reflex of Lewis ? Such stimulation causes the phenomenon of herpes zoster in the affected skin and oedema in the deep tissues. Unmyelinated vasodilator nerve-fibres of cholinergic type have been shown to be responsible for this and for the vasodilator effects, in a completely sympathectomised animal. If Mr. Cohen is not acquainted with severe oedema and ulceration as " trophic lesions " he can find references to this in any neurological textbook-e.g., Bumke and Foerster’s
Handbieeh der Neu7°ologie, vol. 5, or Wilson’s Neurology, where the effects of irritation or section of the peripheral nerves are described. CEdema and trophic sores following irritation of the posterior nerve-roots are well seen in cases of herpes zoster, which may be followed by oedema and gangrene of the affected tissues and skin (see Bumke and Foerster). Ophthalmic zoster produces tremendous local oedema in the orbit and eye and often arterial If Mr. Cohen and venous thromboses in the retina. does not believe thatProctocaine ’ injection into peripheral nerves causes immediate vasodilatation and constriction both locally and at a distance, I suggest he should try such an injection for himself, as I have done on numerous occasions in the treatment of severe neuritis. Mr. Cohen is somewhat naive in suggesting that the intraneural injection would be required to be made into all the nerves of a limb in order to produce the symptoms he described. Concussion of a single nerve, as in causalgia resulting from bullet wounds, causes " trophic changes " and produces wasting and sensory loss in tissues supplied by nerves not directly damaged. Moreover, Mr. Cohen does not seem to be familiar with the phenomenon of ascending oedema of nerves, whereby the oedema due to damage to a single nerve branch ascends and descends the nerve to involve the nerve-roots of origin and other branches of these roots, and also roots entering neighbouring parts of the cord. If Mr. Cohen still does not believe that injections of drugs into peripheral
produce the effects he describes, I recommend him to read A. D. Speransky’s Basis for the Theory of Medicine (1935), in which the effects of the application of drugs and chemicals to peripheral nerves in dogs and other animals are described at length. It produces changes both in the affected and opposite limb identical with those he records. As regards the effects of acetylcholine on clotting I made this statement as a result of personal observations, which will be published later. In my letter I carefully did not mention liberation of acetylcholine into the circulation, but " in the blood-vessels "-meaning in Mr. Cohen’s quotations on the effect of the walls. acetylcholine injection into the circulation are thus irrelevant. Acetylcholine liberated in the walls of blood-vessels leads to oedema of the vessel walls, as it does when it is liberated in other tissues, such as the skin or any tissue into which it is injected. It is this oedema of the blood-vessel wall which predisposes to clotting. The effect is not directly on the blood. Such phenomena are well seen in the retinal thromboses complicating ophthalmic zoster. To conclude, I repeat that in spite of all Mr. Cohen’s belligerency the criticism remains that he still has not shown that intra-arterial injection took place in the cases he described. Some of those who supplied him with cases stated that they believed the injections were intravenous, yet he assumes they must have been intra-arterial without adequate proof. Intra-arterial injection of thiopentone is usually harmless. I am not sure which hypothesis Mr. Cohen considers dies an honourable death, but I hope it is his own. R. WYBURN-MASON. London, W.1.
nerves
APPLICATION FOR HOSPITAL POST "
A.B." in the issue of SIR,-Your correspondent Nov. 6 mentions a point over which many people appear to get confused. The hospital with which I am associated sometimes advertises house-officer posts as A or B2." This means that the hospital would prefer to appoint someone with not less than six months’ previous experience, but that if the most suitable applicant is a newly qualified practitioner without previous experience he will not be entitled to B2 status and pay which allow for experience that he does not possess. It sometimes happens that all the applicants are without postgraduate experience. "
Bishop’s Stortford. THE
RAYMOND HILL.
BALLISTOCARDIOGRAM
SiB,—I was greatly interested in the annotation on this subject in your issue of Oct. 30. In 1917, when I was a member of the special board for the selection of pilots for the Royal Flying Corps, we utilised, for weighing the candidates, an adapted pennyin-the-slot weighing-machine. I noted that the needle pulsated synchronously with the pulse-rate. Anyone can satisfy himself of this fact by the expenditure of a copper on any similar apparatus. This observation led, later, to a small joint investigation with Major W. S. Tucker, D.sc., R.E., which culminated in the presentation of a paper to the Royal Society, entitled Recoil Curves as Shown by the Hot-Wire Microphone.l In this communication the subject is portrayed standing ; subsequently we found that far better results could be obtained by a suspended couch, the horizontal movements being controlled and standardised by piano
wire tensed to the middle C. In the communication a variety of curves are illustrated showing the effect of exercise, breathing, &c., also the correlation of these curves in relation to the electrocardiograph curves and heart sounds. Unfortunately, this interesting piece of work had to be abandoned owing to staff changes and finance stringency in the civil-aviation department of the Air Ministry ; and, as far as I know, nothing further has been done. I have, however, always felt that there was a valuable place for this method if properly developed, since, as Major Tucker shows, these recoil curves lend themselves to ballistic analysis. Incidentally I consider " recoil curves " a better name. C. B. HEALD. London, W.I. 1. Heald, C. B., Tucker, W. S. Proc. roy. Soc. B. 1922, 93, 281.
for the unwillingness may be transmitted to their detriment. (i) Movement of a bed or other furniture must never be avoided, for fear of giving trouble, if it is necessary to allow the examiner to take up a proper position. Great clinicians always put themselves in these postures by the light of nature ; but we are not all great clinicians ; and we need thought, and conscious attention to detail, in order to approach their standard of to her
patients,
inefficiency. London, W.1.
T. B. LAYTON.
INFECTION THROUGH SOAKED DRESSINGS SiR,--Sterile non-absorbent cotton-wool has many of the properties required by Dr. Colebrook and Mr. Hood (Oct. 30). A thick layer placed on the outside’of the absorbent cotton-wool dressing will keep the exterior of the burn dressing dry for a long time. Sterile ’nonabsorbent cotton-wool has been used as a bacterial air-filter for many years. I believe the U.S.A. shelldressing used to consist of a pad of absorbent cotton-wool backed by non-absorbent cotton-wool. The two layers were surrounded by gauze. J. A. MYERS. Bradford. ’
ACCIDENTAL INTRA-ARTERIAL INJECTION OF DRUGS to my SiB,—Mr. Cohen’s letter last week in reply criticism (Oct. 2) of his paper accuses me of " flaunting certain physiological facts," and misconstrues what I said. I did not suggest that the effects of the injections he describes were due to vasodilatation in the tissues or to trophic nervous activity, as he states I did ; nor did I make the ridiculous suggestion he attributes to me that thiopentone in the cases under consideration injected solely into a nerve without entering the was circulation. Obviously it did go into the circulation, but the very delay before the onset of unconsciousness, which Mr. Cohen pointed out is usual in these cases, indicates that the entry into the circulation is abnormal. All I suggested was that some of the injection irritated nerve-fibres. Mr. Cohen does not believe vasodilator fibres supply the skin, but how does he explain the effect of stimulation of the peripheral ends of the posterior nerve-roots and the axon reflex of Lewis ? Such stimulation causes the phenomenon of herpes zoster in the affected skin and oedema in the deep tissues. Unmyelinated vasodilator nerve-fibres of cholinergic type have been shown to be responsible for this and for the vasodilator effects, in a completely sympathectomised animal. If Mr. Cohen is not acquainted with severe oedema and ulceration as " trophic lesions " he can find references to this in any neurological textbook-e.g., Bumke and Foerster’s
Handbieeh der Neu7°ologie, vol. 5, or Wilson’s Neurology, where the effects of irritation or section of the peripheral nerves are described. CEdema and trophic sores following irritation of the posterior nerve-roots are well seen in cases of herpes zoster, which may be followed by oedema and gangrene of the affected tissues and skin (see Bumke and Foerster). Ophthalmic zoster produces tremendous local oedema in the orbit and eye and often arterial If Mr. Cohen and venous thromboses in the retina. does not believe thatProctocaine ’ injection into peripheral nerves causes immediate vasodilatation and constriction both locally and at a distance, I suggest he should try such an injection for himself, as I have done on numerous occasions in the treatment of severe neuritis. Mr. Cohen is somewhat naive in suggesting that the intraneural injection would be required to be made into all the nerves of a limb in order to produce the symptoms he described. Concussion of a single nerve, as in causalgia resulting from bullet wounds, causes " trophic changes " and produces wasting and sensory loss in tissues supplied by nerves not directly damaged. Moreover, Mr. Cohen does not seem to be familiar with the phenomenon of ascending oedema of nerves, whereby the oedema due to damage to a single nerve branch ascends and descends the nerve to involve the nerve-roots of origin and other branches of these roots, and also roots entering neighbouring parts of the cord. If Mr. Cohen still does not believe that injections of drugs into peripheral
produce the effects he describes, I recommend him to read A. D. Speransky’s Basis for the Theory of Medicine (1935), in which the effects of the application of drugs and chemicals to peripheral nerves in dogs and other animals are described at length. It produces changes both in the affected and opposite limb identical with those he records. As regards the effects of acetylcholine on clotting I made this statement as a result of personal observations, which will be published later. In my letter I carefully did not mention liberation of acetylcholine into the circulation, but " in the blood-vessels "-meaning in Mr. Cohen’s quotations on the effect of the walls. acetylcholine injection into the circulation are thus irrelevant. Acetylcholine liberated in the walls of blood-vessels leads to oedema of the vessel walls, as it does when it is liberated in other tissues, such as the skin or any tissue into which it is injected. It is this oedema of the blood-vessel wall which predisposes to clotting. The effect is not directly on the blood. Such phenomena are well seen in the retinal thromboses complicating ophthalmic zoster. To conclude, I repeat that in spite of all Mr. Cohen’s belligerency the criticism remains that he still has not shown that intra-arterial injection took place in the cases he described. Some of those who supplied him with cases stated that they believed the injections were intravenous, yet he assumes they must have been intra-arterial without adequate proof. Intra-arterial injection of thiopentone is usually harmless. I am not sure which hypothesis Mr. Cohen considers dies an honourable death, but I hope it is his own. R. WYBURN-MASON. London, W.1.
nerves
APPLICATION FOR HOSPITAL POST "
A.B." in the issue of SIR,-Your correspondent Nov. 6 mentions a point over which many people appear to get confused. The hospital with which I am associated sometimes advertises house-officer posts as A or B2." This means that the hospital would prefer to appoint someone with not less than six months’ previous experience, but that if the most suitable applicant is a newly qualified practitioner without previous experience he will not be entitled to B2 status and pay which allow for experience that he does not possess. It sometimes happens that all the applicants are without postgraduate experience. "
Bishop’s Stortford. THE
RAYMOND HILL.
BALLISTOCARDIOGRAM
SiB,—I was greatly interested in the annotation on this subject in your issue of Oct. 30. In 1917, when I was a member of the special board for the selection of pilots for the Royal Flying Corps, we utilised, for weighing the candidates, an adapted pennyin-the-slot weighing-machine. I noted that the needle pulsated synchronously with the pulse-rate. Anyone can satisfy himself of this fact by the expenditure of a copper on any similar apparatus. This observation led, later, to a small joint investigation with Major W. S. Tucker, D.sc., R.E., which culminated in the presentation of a paper to the Royal Society, entitled Recoil Curves as Shown by the Hot-Wire Microphone.l In this communication the subject is portrayed standing ; subsequently we found that far better results could be obtained by a suspended couch, the horizontal movements being controlled and standardised by piano
wire tensed to the middle C. In the communication a variety of curves are illustrated showing the effect of exercise, breathing, &c., also the correlation of these curves in relation to the electrocardiograph curves and heart sounds. Unfortunately, this interesting piece of work had to be abandoned owing to staff changes and finance stringency in the civil-aviation department of the Air Ministry ; and, as far as I know, nothing further has been done. I have, however, always felt that there was a valuable place for this method if properly developed, since, as Major Tucker shows, these recoil curves lend themselves to ballistic analysis. Incidentally I consider " recoil curves " a better name. C. B. HEALD. London, W.I. 1. Heald, C. B., Tucker, W. S. Proc. roy. Soc. B. 1922, 93, 281.