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SUBACUTE BACTERIAL ENDOCARDITIS
637 on expiration and forward protrusion of the mucosa so extreme as to leave no more than a " new moon " slit, even in the trachea. We agree that the carina appears shorter and wider, but this is probably due to turgidity and congestion rather than to actual shortening. About a dozen of these patients have returned each winter for a repetition of treatment which did them good. In true asthma we are not prepared to say how much of the benefit is due to psychological effect. E. H. HUDSON, H. M. MORLOCK. London Chest Hospital, E.2.
and the bronchi ;
during
the spasm,
particularly on coughing, it is muscular posterior wall and
a
INFANTS IN DAY NURSERIES SIR,-I wish to endorse Professor Parsons’s views in his letter of Oct. 12. It seems to me that Dr. Barrow and Dr. Brenner avoid the main issue in their criticism of his letter. There can surely be no doubt that if infants during the breast-feeding period are admitted to day nurseries breast-feeding will be discouraged, artificial feeding will be encouraged, and infection will spread amongst these babies of the same age-period if congregated together. If the Ministry of Health realise these dangers it is inconceivable that they have not given directions to the local authorities to prevent the admittance of these babies to day nurseries. Professor Parsons makes an excellent suggestion when he says, " It would, however, be interesting to know whether the dearth of skilled munition workers in any area is so great as to make the employment of.mothers of infants under nine months of age essential, since this group can only represent a relatively small fraction of the total number of female workers." With regard to the question of anxiety in the mother interfering with the supply of breast milk referred to by Dr. Brenner, I have seen a large number of these cases after air-raids and in my experience after two days the supply returns again and the infant continues to be breast fed with no symptoms suggesting any alteration in the quality of the milk. RONALD CARTER. Kensington, W.8. AIR PURIFICATION BY HYPOCHLORITES SIR,-A sentence in your leading article of Oct. 12 (p. 456) refers to the use of sodium hypochlorite for aerial disinfection in these terms : " The last of these is the cheapest, but it is unstable and highly corrosive to metal containers and has other disadvantages." And the authority cited for this statement is a report by Baker, Finn and Twort in the September issue of the Journal of Hygiene whose conclusion reads as follows : " That there are definite possibilities for the use of hypochlorite mists for combating aereal infections, but that the odour, irritant effects, opacity of the mists and corrosion of metals &c. will limit the sphere of utility." These opinions are based on work done with nebulisers using enormously stronger concentrations of germicide than those required in a properly designed atomiser. On their own statement they require a concentration of (weight to volume of air) 1 part in 1 million. The standard Milton Dynalysor requires a concentration of only 1 in 40-50 millions, and this concentration of 1% sodium hypochlorite contains no more than 1 in 5000 millions of the active germicide. Dr. Pulvertaft tested concentrations of 1 in 40, 20, and 10 millions and remarks: " These produced no visible mist and in each case a slight odour only, completely non-irritant, and, as a personal opinion, rather pleasant. In my opinion there is no possible menace to the health or convenience of anyone submitted to the mist in efficient concentration." During 1930-35 this system of air purification was tried in large-scale experiments on inhabited and furnished rooms without experiencing any of the objections raised by the authors. As regards " irritation," a concentration of about 1 in 200 has long been employed by the general public for spraying the nose and respiratory passages. " Opacity of the mist " is caused by particles of evaporated salt which eventually fall to the floor. The authors employed a hypochlorite with a salt content more than 3 times that of the standard spray. " Corrosion of metals " is caused by the deposit of damp salt, as in the
With a dose of 1 in 40 millions for a of 2000 cu. ft., 10 feet high, there would eventually be deposited 0-002 mg. of salt on each sq. in. of floor space. This is probably considerably less than could be found at any time in any ordinary dining-room carpet1 The authors raise another " contingency for serious consideration " in " the bleaching and rotting effects of free chlorine." They seem to be unaware that hypochlorites contain no free chlorine and that this gas is not given off by hypochlorites unless decomposed by strong acids. Hypochlorite air-disinfection is based upon the liberation of hypochlorous acid which is essentially different in its characters from chlorine. It has little odour, no irritant properties, and its germicidal potency is immensely greater than that of chlorine. It is common knowledge that hypochlorite solutions can be rendered for all practical purposes completely stable. My own opinion is that hypochlorites do not behave as aerosols when sprayed into the air; in other words, they do not kill by the action of small liquid drops, but by the setting free of hypochlorous acid gas which is absorbed by the moist bacteria. I am aware that this is controversial, but I have seen no evidence of any value for the aerosol theory so far as hypochlorites are concerned, and there is a great deal against it.
rusting of iron. room
A. T. MASTERMAN.
London, W.I.
SUBACUTE BACTERIAL ENDOCARDITIS
SIR,-Dr. Fletcher’s account in your issue of Oct. 26 of
a case
of subacute bacterial endocarditis treated with
sulphapyridine and heparin prompts me to draw attention to our experience of the method in this hospital.
Four cases had been treated and two more were under treatment when the hospital was bombed. Of the four treated, one has remained well for six months, two died of intracranial haemorrhage, and one of toxic jaundice. Positive blood-cultures were obtained before treatment in every case and in certain cases the organism’s growth was tested against the drug in vitro. We experienced the same difficulties as Dr. Fletcher in the standardisation of heparin and can endorse his statements about the danger of intracranial haemorrhage. Guildford.
C. P. PETCH, TvT,li.1 Registrar, RPOicfrar. Ci-.. St. ’Ph.mnQ’. Medical Thomas’s RlBQTBit.!B.L Hospital.
BLOOD SEDIMENTATION INDEX
SIR,-The experience narrated by Dr. fmlipotts is by means uncommon. A blood sample set up in a sedimentation-tube after an hour or two’s delay will sometimes reproduce exactly the behaviour of a sample of the same blood set up immediately after withdrawal from the vein-but not always. Here is a case in point where it did notlst hour Maximum velocity reading. per 100 minutes. 68 mm. No delay........ 26 mm. no
Two hours’ delay...... Four hours’ delay..
35’5 mm. 36 mm.
68 68
mm.
mm.
As he suggests, this may be due to cooling effects which obtained during the first sedimentation, and which were practically complete before. the second and third (for the experiment was performed at a room temperature of 18° C.) ; or it may be due to agglutination taking place during the two hours’ delay, so that the clumps of corpuscles, being fully formed from the start in the 2nd and 3rd sedimentations, achieve their maximum velocity earlier. Or, of course, it may be due to both factors. As I always found that slowly sedimenting bloods are less affected in their first-hour readings by delay than are the rapid ones-the sort that show 100 mm. and more in an hour-I have always assumed (perhaps wrongly) the second hypothesis to be true. Dr. Phillpotts’s summing up (" that one may safely keep a sample of blood up to 24 hours before measuring its sedimentation-rate and still have reasonable certainty of obtaining the correct result ") is only saved from being really naughty by the conditional clause-"The temperature at which the rate is measured must obviously [my italics] be constant, however." I confess I have no experience of blood sedimentation experiments performed in a constant-temperature observation chamber.
and the bronchi ;
during
the spasm,
particularly on coughing, it is muscular posterior wall and
a
INFANTS IN DAY NURSERIES SIR,-I wish to endorse Professor Parsons’s views in his letter of Oct. 12. It seems to me that Dr. Barrow and Dr. Brenner avoid the main issue in their criticism of his letter. There can surely be no doubt that if infants during the breast-feeding period are admitted to day nurseries breast-feeding will be discouraged, artificial feeding will be encouraged, and infection will spread amongst these babies of the same age-period if congregated together. If the Ministry of Health realise these dangers it is inconceivable that they have not given directions to the local authorities to prevent the admittance of these babies to day nurseries. Professor Parsons makes an excellent suggestion when he says, " It would, however, be interesting to know whether the dearth of skilled munition workers in any area is so great as to make the employment of.mothers of infants under nine months of age essential, since this group can only represent a relatively small fraction of the total number of female workers." With regard to the question of anxiety in the mother interfering with the supply of breast milk referred to by Dr. Brenner, I have seen a large number of these cases after air-raids and in my experience after two days the supply returns again and the infant continues to be breast fed with no symptoms suggesting any alteration in the quality of the milk. RONALD CARTER. Kensington, W.8. AIR PURIFICATION BY HYPOCHLORITES SIR,-A sentence in your leading article of Oct. 12 (p. 456) refers to the use of sodium hypochlorite for aerial disinfection in these terms : " The last of these is the cheapest, but it is unstable and highly corrosive to metal containers and has other disadvantages." And the authority cited for this statement is a report by Baker, Finn and Twort in the September issue of the Journal of Hygiene whose conclusion reads as follows : " That there are definite possibilities for the use of hypochlorite mists for combating aereal infections, but that the odour, irritant effects, opacity of the mists and corrosion of metals &c. will limit the sphere of utility." These opinions are based on work done with nebulisers using enormously stronger concentrations of germicide than those required in a properly designed atomiser. On their own statement they require a concentration of (weight to volume of air) 1 part in 1 million. The standard Milton Dynalysor requires a concentration of only 1 in 40-50 millions, and this concentration of 1% sodium hypochlorite contains no more than 1 in 5000 millions of the active germicide. Dr. Pulvertaft tested concentrations of 1 in 40, 20, and 10 millions and remarks: " These produced no visible mist and in each case a slight odour only, completely non-irritant, and, as a personal opinion, rather pleasant. In my opinion there is no possible menace to the health or convenience of anyone submitted to the mist in efficient concentration." During 1930-35 this system of air purification was tried in large-scale experiments on inhabited and furnished rooms without experiencing any of the objections raised by the authors. As regards " irritation," a concentration of about 1 in 200 has long been employed by the general public for spraying the nose and respiratory passages. " Opacity of the mist " is caused by particles of evaporated salt which eventually fall to the floor. The authors employed a hypochlorite with a salt content more than 3 times that of the standard spray. " Corrosion of metals " is caused by the deposit of damp salt, as in the
With a dose of 1 in 40 millions for a of 2000 cu. ft., 10 feet high, there would eventually be deposited 0-002 mg. of salt on each sq. in. of floor space. This is probably considerably less than could be found at any time in any ordinary dining-room carpet1 The authors raise another " contingency for serious consideration " in " the bleaching and rotting effects of free chlorine." They seem to be unaware that hypochlorites contain no free chlorine and that this gas is not given off by hypochlorites unless decomposed by strong acids. Hypochlorite air-disinfection is based upon the liberation of hypochlorous acid which is essentially different in its characters from chlorine. It has little odour, no irritant properties, and its germicidal potency is immensely greater than that of chlorine. It is common knowledge that hypochlorite solutions can be rendered for all practical purposes completely stable. My own opinion is that hypochlorites do not behave as aerosols when sprayed into the air; in other words, they do not kill by the action of small liquid drops, but by the setting free of hypochlorous acid gas which is absorbed by the moist bacteria. I am aware that this is controversial, but I have seen no evidence of any value for the aerosol theory so far as hypochlorites are concerned, and there is a great deal against it.
rusting of iron. room
A. T. MASTERMAN.
London, W.I.
SUBACUTE BACTERIAL ENDOCARDITIS
SIR,-Dr. Fletcher’s account in your issue of Oct. 26 of
a case
of subacute bacterial endocarditis treated with
sulphapyridine and heparin prompts me to draw attention to our experience of the method in this hospital.
Four cases had been treated and two more were under treatment when the hospital was bombed. Of the four treated, one has remained well for six months, two died of intracranial haemorrhage, and one of toxic jaundice. Positive blood-cultures were obtained before treatment in every case and in certain cases the organism’s growth was tested against the drug in vitro. We experienced the same difficulties as Dr. Fletcher in the standardisation of heparin and can endorse his statements about the danger of intracranial haemorrhage. Guildford.
C. P. PETCH, TvT,li.1 Registrar, RPOicfrar. Ci-.. St. ’Ph.mnQ’. Medical Thomas’s RlBQTBit.!B.L Hospital.
BLOOD SEDIMENTATION INDEX
SIR,-The experience narrated by Dr. fmlipotts is by means uncommon. A blood sample set up in a sedimentation-tube after an hour or two’s delay will sometimes reproduce exactly the behaviour of a sample of the same blood set up immediately after withdrawal from the vein-but not always. Here is a case in point where it did notlst hour Maximum velocity reading. per 100 minutes. 68 mm. No delay........ 26 mm. no
Two hours’ delay...... Four hours’ delay..
35’5 mm. 36 mm.
68 68
mm.
mm.
As he suggests, this may be due to cooling effects which obtained during the first sedimentation, and which were practically complete before. the second and third (for the experiment was performed at a room temperature of 18° C.) ; or it may be due to agglutination taking place during the two hours’ delay, so that the clumps of corpuscles, being fully formed from the start in the 2nd and 3rd sedimentations, achieve their maximum velocity earlier. Or, of course, it may be due to both factors. As I always found that slowly sedimenting bloods are less affected in their first-hour readings by delay than are the rapid ones-the sort that show 100 mm. and more in an hour-I have always assumed (perhaps wrongly) the second hypothesis to be true. Dr. Phillpotts’s summing up (" that one may safely keep a sample of blood up to 24 hours before measuring its sedimentation-rate and still have reasonable certainty of obtaining the correct result ") is only saved from being really naughty by the conditional clause-"The temperature at which the rate is measured must obviously [my italics] be constant, however." I confess I have no experience of blood sedimentation experiments performed in a constant-temperature observation chamber.