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10% solution of the sodium salt. One would have expecteda sodium salt solution of twice the strength to have been atleast as active if not rather more so, than the weaker acid

suspension, and one wonders whether the apparent lesser

activity of the solutions was not due to the methods of

preparation and sterilisation adopted.The low blood concentration achieved by administering

P.A.S. by mouth (2-7 mg. per 100 ml. from 10-15 g. daily 3)make it likely that clinical investigators will favourparenteral injection. For this purpose sterile solutionsof the soluble salts of P.A.S., such as the sodium salt, mustbe used, and the purpose of this letter is to obviate someof the confusion and errors that may well arise in thepreparation of these solutions.

JAMES A. O’CONNOR.Laboratories of Messrs. Ward, Blenkinsop & Co. Ltd.,

London, W.1.

** *We understand that the Scandinavian workersconsider the purity of solutions of sodium p-aminosali-cylate of no great clinical significance, and that in-vitrotests have demonstrated an effective bacteriostaticactivity in brown " impure " solutions. Further studieson these lines are clearly required.-ED. L.

MYANESIN ANESTHESIA

SiR,-In view of recent accounts of haemolysis andrenal damage following upon the use of Myanesin,’ thiscase is of interest.A boy of 12 years was admitted with three months’ history

of subacute appendicitis with exacerbation of symptomsduring the 24 hours before admission. There was no pasthistory of renal or blood disease.Appendicectomy was performed the same evening, and

an acutely inflamed appendix removed, the operation wasuneventful. Premedication consisted of Oihnopon’ gr. 1/6and scopolamine gr. 1/300’ Anesthesia was induced with

thiopentone 0-25 g. intravenously and continued with nitrous’oxide, oxygen, and ether by Boyle’s machine; 8 ml. of

myanesin solution (10% w/v) was given after induction.Anaesthesia was uneventful.The next morning the patient passed 8 oz. of blood-coloured

urine ; there were no associated urinary symptoms. Theurine was found to contain much free haemoglobin, granularcasts, and a few leucocytes and red blood-cells. The patientfelt well, and there were no abnormal findings on physicalexamination.

Urine passed thereafter was perfectly normal. No symptomsdeveloped and there were no abnormal findings. There wasno jaundice ; the van den Bergh reaction was not tested.The patient’s further progress was uneventful and he wasdischarged well seven days later.

It is suggested that this symptomless postoperativehaemoglobinuria was the result of intravascular haemolysisdue to myanesin given during the operation.

Metropolitan Hospital, London. C. B. NOBLE.

TREATMENT OF ARTHRITIS BY INTRA-ARTICULAR INJECTION

SiB,—The paper by Dr. Baker and Dr. Chayenan. 17, p. 93) is the first serious attempt to appraisethe value of acid injections into the arthritic joint.I trust the authors will forgive me if I offer somecriticisms.They say :

" While under injection treatment patientshave received no other form of therapy." This is atvariance with their earlier statement that " non-weight-bearing exercises are taught to each patient," and thatthese are started " immediately after the injection."It is my impression that the average arthritic knee isconsiderably improved’ by physiotherapy alone, whereasthe arthritic hip tends to resist treatment. The bujk oftheir patients were affected by arthritis of the hip orknee, and it would not be unfair to assume that thepatients with arthritis of the knee might have benefitedas much from exercises alone. Unfortunately figuresare not given to indicate separately the results oftreatment on knee and hip, whether affected by atrophicor degenerative arthritis. To my mind, the crucial testis the effect of such treatment on the inaccessible hip.The criteria offered as proof of joint puncture are not

sufficiently stringent to ensure that the hip-joint was3. Lehmann, J. Lancet, 1946, i, 15.

entered. Crepitus may arise from periarticular structures,and the other indications are too vague. Experience withthis procedure has taught me that nothing less thansimultaneous injection of an opaque dye will indicatethe ultimate site of the injection, and that humilitycomes quickly. The knee of course is more accessible,but the merit of the injections is less obvious. However,if any benefit from this form of therapy is due to theanaesthesia obtained, then periarticular injection may.be as desirable as intra-articular.Two fundamental questions remain to be answered:

the relationship of joint pH to the disease process, andthe effect of acid injection as judged by a controlledseries of cases,

.

County Hospital, Farnborough. DAVID P. NICHOLSON.

TETRAETHYL AMMONIUM BROMIDE

SiR,-The article by Professor Boyd and his colleagues(Jan. 3) is a valuable contribution to our knowledge ofthe pharmacology and clinical use of this product. Ifeel, however, that the condemnation of the drug by thisdistinguished team may possibly be premature. In aconsiderable number of cases of vascular disease bothfunctional and organic, I have found tetraethyl ammo-nium bromide (furnished by the courtesy of Messrs. Boots)useful as a preoperative test.

It is unlikely, of course, that any preoperative testthat may be devised will have a sufficiently definite andlocalised point of action to give a result exactly com-parable with the physiological disturbance ultimatelyachieved by various forms of sympathectomy.The advantages of tetraethyl ammonium bromide as

a test substance are the simplicity of its administration,the rapidity with which the results are obtained, the shortduration of its action, and the relative absence ofcomplications. In my hands it has given results fairlydirectly comparable with those achieved by, for example,spinal anaesthesia, paravertebral block, and methods ofproducing thermoregulatory vasodilatation. Therefore,although early claims for the therapeutic efficacy ofthis drug must be discounted, it is desirable that,while preoperative tests as a group remain relativelyunreliable and often tedious, this elegant andharmless test substance should not lightly be discarded.

Glasgow. W. ARTHUR MACKEY.

SHOCK IN OBSTETRICS

SIR,-Professor Sheehan, in his article of Jan. 3,remarks that " in obstetric patients with shock alone,or with shock and. only a minor degree of haemorrhage,there is no evidence that blood-transfusion is of anyvalue whatsoever in saving the lives of the patients."This is again emphasised in the summary, and onemight infer that transfusion in general is contra-indicated,since no other form of transfusion is mentioned.His conclusions are not surprising, however, since

whole-blood transfusion never has been accepted as thetreatment of shock, nor would one expect it to be.After haemorrhage whole-blood transfusion is ideal, butthe loss of blood-volume in shock is due to plasma loss,and it is accompanied by pronounced hsemoconcentration.Under these conditions plasma transfusion is indicated,and it is possible that with this therapy- ProfessorSheehan’s figures in the shock-alone group would not’

‘

appear so discouraging.Titchfield, Hants. P. M. VASEY.

** * We have shown this letter to Professor Sheehan,who writes : " The remarks on the treatment of shockwere restricted to the value of whole-blood transfusionbecause this was the only matter on which we hadadequately controlled facts. The figures were obtainedin the period before 1941 when whole-blood transfusionwas very widely accepted as the correct treatment forshock, and plasma could not be obtained in the quantitiesavailable today. Plasma transfusions, intravenous saline,and intravenous glucose (isotonic and hypertonic) havehowever all been given extensive trial at GlasgowRoyal Maternity Hospital ; the effects were not verydramatic, but the figures are unfortunately not of realvalue as, the method of control broke down owing towar conditions. The fact that these lines of treatmentwere not discussed in the paper should not be taken as