- Email: [email protected]
THE PURGATIVE ACTION OF MAGNESIUM SALTS
644 was found to be very suitable for the purpose, and was submitted for examination to the Therapeutic Trials Committee of the Medical Research Council. A report of the findings of this committee appeared a year ago in your columns (1934, i., 942), and the substance has since been issued to the medical profession by the Hoffmann-La Roche Chemical Works in London under the name of prostigmin. The spade work done in the laboratory which has rendered possible this successful treatment of myasthenia. and which apparently opens up considerable possibilities for further development in what may be styled submyasthenic conditions, should be known and recognised. The research work necessitated by such an exhaustiveexamination as that undertaken in the production of prostigmin is exceedingly costly and can only be carried out in laboratories equipped with the latest and most expensive apparatus, and by scientists of the highest standing and experience. Thousands of new drugs may be synthesised and pharmacologically tested, but only a few of them come into general use, and credit is due to those enterprising manufacturing firms who voluntarily render such research work possible and thereby place in the hands of the medical profession new drugs and better remedies for the alleviation of disease.-I am, Sir, vours faithfully, L. BAYLEY, F.C.S.
trimethylammonium-methyl-sulphate
The Crescent, Friern Barnet, N., March 11th. lltli.
QUININE AS
A PROPHYLACTIC IN MALARIA
To the L’d2t.or
of
TIIE LANCET
SIR,-Dr. Lyndhurst Duke, in his letter published in your last issue, asks for an authoritative pronouncement on the above subject. Such a pronouncement was given by the Malaria Commission of the League of Nations in their third general report entitled The Therapeutics of Malaria " which was published in the Quarterly Bulletin of the League’s Health Organisation in June, 1933, and was reviewed on page 246 of your issue of July 29th of the same year. The pronouncement, which was based on field trials " as well as on " controlled laboratory experiments," will be found under the heading "The problem of clinical prophylaxis " on pages 203 to 207 of the Summary," in report, and under the heading, "
"
"
paragraph (6)
page 234. I am, Sir, yours
on
S. P. JAMES.
The issue of the Quarterly Bulletin, to which Colonel James refers, is now out of print, but the reprinted
on
p.
657
of
our
logical physical signs.
Two-thirds of Dr.
of
Findlay’s
to have been of this latter class in which the environmental factor has always been recognised as playing the larger part, although, as Dr. Findlay’s figures show, heredity is also a factor to a small degree. To the former class, his" remark that intelligence as such is hereditary surely applies and is in contradiction to his conclusion, although no one will deny that even in this group the factor of environment may play no inconsiderable part. cases seem
I am,
Sir,
THE LANCET
SIR,—Dr. FindlaLy’s article in your last issue giving an analysis of a group of cases of mental defect was of considerable interest, especially as his group is composed of individuals from the better social class, regarding whom there lias been previously, so far as I know, no similar record. I think, however, that the sweeping character of one of Ills conclusions is scarcely justified by his results. " The analysis," he says, " lends little support to the idea that heredity plays any important role in the causation of mental defect." Dr. Findlay makes it a point of criticism of the work of the Departmental Committee on Sterilisation that they combine in one
yours
faithfully, IIENRY HERD. HENRY
Manchester, March 1 :3th.
HEREDITY AND MENTAL DEFECT To the Editor
"
"
faithfully,
London, March 12th.
relevant sections are present issue.-ED. L.
group for analysis both high- and low-grade defectives, but his own attempt to make a conclusion based on an examination of low-grade defectives apply to all, both high and low, is equally open to criticism and is the more surprising in that in an earlier part of the article he states that high-grade deficiency " may show, and as a matter offact does show, a strong hereditary tendency." His further statement that " mentally defective parents seldom have mentally defective children" is surely contradicted by the Departmental Committee’s finding that 16-9 per cent. of children between 7 and 13 years of age born from at least one defective parent were defective and 32-4 per cent. of children over 13. Dr. Findlay makes reference to my own chapter on mental defect in Blacker’s The Chances of Morbid Inheritance." The cases included in my own pedigrees quoted in that chapter were all of children whose I.Q. was over 50 and none of the parents included could be classed as imbeciles, but to say that they were of high-grade would be to flatter them, unless we are to hold that any person with an I.Q. over 50 is highgrade. One feels, I think, in many discussions and many of the public inquiries into this subject that there is in general use no definite standard of what is meant by the terms high- and low-grade. Here the point of view of the hospital and institutional medical officer is very different from that of, for example, the school medical oflicer. To the latter, a case can appear to be low-grade which to the former is highgrade. Dr. Findlay states that his cases were lowgrade, but it would certainly havebeen helpful could one have had a statement of their I.Q. This does not mean that the I.Q. should be regarded as the only diagnostic point, but it is convenient for grouping and statistical purposes. It does not seem completely satisfactory to divide defectives simply into high-grades and low-grades. Is it not better to adopt Lewis’s suggestion that a certain number of defectives, the larger proportion indeed, are merely biological variations on an intelligence scale ?’’ A separate group is constituted by defectives who, besides their defect, show patho-
THE PURGATIVE ACTION OF MAGNESIUM SALTS
To the Editor
of
THE LANCET
SIR,—With regard to the recent controversy relating to the mode of action of magnesium sulphate in causing purgation, may I point out that intravenous injection of amounts of this drug up to one gramme have no constant effect on the frequency of evacuation or on the liquidity of the motions. The absence of effect has no relation to the strength of the solution injected, as isotonic and hypertonic solutions are equally without purgative effect. I am, Sir, yours faithfully, London, BV., March llth.
II. A. DUNLOP. H.
trimethylammonium-methyl-sulphate
The Crescent, Friern Barnet, N., March 11th. lltli.
QUININE AS
A PROPHYLACTIC IN MALARIA
To the L’d2t.or
of
TIIE LANCET
SIR,-Dr. Lyndhurst Duke, in his letter published in your last issue, asks for an authoritative pronouncement on the above subject. Such a pronouncement was given by the Malaria Commission of the League of Nations in their third general report entitled The Therapeutics of Malaria " which was published in the Quarterly Bulletin of the League’s Health Organisation in June, 1933, and was reviewed on page 246 of your issue of July 29th of the same year. The pronouncement, which was based on field trials " as well as on " controlled laboratory experiments," will be found under the heading "The problem of clinical prophylaxis " on pages 203 to 207 of the Summary," in report, and under the heading, "
"
"
paragraph (6)
page 234. I am, Sir, yours
on
S. P. JAMES.
The issue of the Quarterly Bulletin, to which Colonel James refers, is now out of print, but the reprinted
on
p.
657
of
our
logical physical signs.
Two-thirds of Dr.
of
Findlay’s
to have been of this latter class in which the environmental factor has always been recognised as playing the larger part, although, as Dr. Findlay’s figures show, heredity is also a factor to a small degree. To the former class, his" remark that intelligence as such is hereditary surely applies and is in contradiction to his conclusion, although no one will deny that even in this group the factor of environment may play no inconsiderable part. cases seem
I am,
Sir,
THE LANCET
SIR,—Dr. FindlaLy’s article in your last issue giving an analysis of a group of cases of mental defect was of considerable interest, especially as his group is composed of individuals from the better social class, regarding whom there lias been previously, so far as I know, no similar record. I think, however, that the sweeping character of one of Ills conclusions is scarcely justified by his results. " The analysis," he says, " lends little support to the idea that heredity plays any important role in the causation of mental defect." Dr. Findlay makes it a point of criticism of the work of the Departmental Committee on Sterilisation that they combine in one
yours
faithfully, IIENRY HERD. HENRY
Manchester, March 1 :3th.
HEREDITY AND MENTAL DEFECT To the Editor
"
"
faithfully,
London, March 12th.
relevant sections are present issue.-ED. L.
group for analysis both high- and low-grade defectives, but his own attempt to make a conclusion based on an examination of low-grade defectives apply to all, both high and low, is equally open to criticism and is the more surprising in that in an earlier part of the article he states that high-grade deficiency " may show, and as a matter offact does show, a strong hereditary tendency." His further statement that " mentally defective parents seldom have mentally defective children" is surely contradicted by the Departmental Committee’s finding that 16-9 per cent. of children between 7 and 13 years of age born from at least one defective parent were defective and 32-4 per cent. of children over 13. Dr. Findlay makes reference to my own chapter on mental defect in Blacker’s The Chances of Morbid Inheritance." The cases included in my own pedigrees quoted in that chapter were all of children whose I.Q. was over 50 and none of the parents included could be classed as imbeciles, but to say that they were of high-grade would be to flatter them, unless we are to hold that any person with an I.Q. over 50 is highgrade. One feels, I think, in many discussions and many of the public inquiries into this subject that there is in general use no definite standard of what is meant by the terms high- and low-grade. Here the point of view of the hospital and institutional medical officer is very different from that of, for example, the school medical oflicer. To the latter, a case can appear to be low-grade which to the former is highgrade. Dr. Findlay states that his cases were lowgrade, but it would certainly havebeen helpful could one have had a statement of their I.Q. This does not mean that the I.Q. should be regarded as the only diagnostic point, but it is convenient for grouping and statistical purposes. It does not seem completely satisfactory to divide defectives simply into high-grades and low-grades. Is it not better to adopt Lewis’s suggestion that a certain number of defectives, the larger proportion indeed, are merely biological variations on an intelligence scale ?’’ A separate group is constituted by defectives who, besides their defect, show patho-
THE PURGATIVE ACTION OF MAGNESIUM SALTS
To the Editor
of
THE LANCET
SIR,—With regard to the recent controversy relating to the mode of action of magnesium sulphate in causing purgation, may I point out that intravenous injection of amounts of this drug up to one gramme have no constant effect on the frequency of evacuation or on the liquidity of the motions. The absence of effect has no relation to the strength of the solution injected, as isotonic and hypertonic solutions are equally without purgative effect. I am, Sir, yours faithfully, London, BV., March llth.
II. A. DUNLOP. H.