Medical issues in historical demography

For the demographer and economic historian all movements of population are important and deserve, so far as possible, to be explained; but for the student of social and medical history the modern rise of population is a unique event whose interpretation is not only of the greatest historical interest but is also essential to an understanding of some of the most formidable contemporary problems. The distinction between the earlier recurrent changes of population and the modern rise is of particular significance in the eighteenth century. The methods as well as the aims of enquiry are different according to whether the increase in numbers is regarded as analogous to that in previous periods (given particular but not necessarily unique significance because of its coincidence with the Agricultural and Industrial Revolutions), or whether it is considered as the beginning of the modern expansion whose dimensions and continuity distinguish it from all previous changes. If eighteenth-century growth is no more than the most remarkable of many movements of population, it is permissible to argue by analogy and to invoke the same kinds of explanations as are accepted for earlier periods. This treatment has been adopted by some economic historians, for example when a decline of mortality has been attributed to cyclic changes in the behaviour of infectious diseases.1 But if the eighteenth century saw the beginning of the modern rise of population such explanations are clearly inadequate, for as the event was unprecedented so too, it seems reasonable to believe, must be the explanation for it. There is no serious doubt that in Britain the modern rise of population did begin during the eighteenth century. It was certainly well established before registration of births and deaths (1838) and even at the time of the first census (1801) the increase in numbers was much greater than that which occurred in earlier periods. For the purpose of interpreting the modern rise of population it is unnecessary, and probably impossible, to state precisely when it started. It is sufficient to know that whatever the explanation in the early years of the eighteenth century, at some time before its end the first phase of the unique expansion had begun. For interpretation of this expansion there is no more important decision than the choice of methods by which it is to be investigated. I should like to make four suggestions concerning them. Data for the eighteenth century are not available, and are unlikely to become available, which put the major issues beyond dispute. It is therefore desirable to begin by examining post-registration data and to consider the uncertainties in the eighteenth century in the light of conclusions concerning the later period. Some of the most important questions which arise are medical in character. In the pre-registration period, the issue which has preoccupied many economic historians—the relative importance of changes in birth rate and death rate—is less significant than the question what disturbed either rate. The inadequacy of eighteenth-century sources is notorious, but this has not deterred investigators from advancing explanations that would be hard to sustain on twentieth-century evidence. Some have been prepared to write confidently about specific causes of death in a period when the death rate is unknown, and even to attribute the remarkable growth of population before registration to the behaviour of a single disease. In fact the data are so unreliable that it is all too easy for the investigator to persuade himself that he has found evidence to support any hypothesis which appeals to him: an increase in fertility,2,3 a decrease in mortality;4 the appearance of the potato,5 the disappearance of plague;1 the effectiveness of variolation, 6 the ineffectiveness of all medical measures.4 The lack of evidence which makes it difficult to sustain an hypothesis makes it almost equally difficult to refute it. When, for example, it is asserted that the rise of population in the eighteenth century was due to the introduction of inoculation against smallpox, 6 even a virologist cannot be expected to produce historical or other evidence which proves conclusively that it was not.7 He can state only that such an interpretation seems most improbable in the light of his knowledge of the disease and its behaviour in a later period for which data are more tangible. It therefore adds nothing to the acceptability of an hypothesis that convincing evidence cannot be mounted against it from contemporary sources, and we must rely largely on later information and the judgement of those whose experience enables them to give an informed opinion. But while recognizing the limitations of existing data, some demographers and economic historians have high hopes from new material which may become available, for example, by investigation of parish registers and of selected population groups such as peers. In assessing what can be expected from such sources one can only express a personal opinion, that the evidence which can be assembled for the eighteenth century is very unlikely of itself to answer the main questions, and conclusions will still be largely influenced by prior hypotheses. This somewhat pessimistic judgement is based not only on the obvious limitations of contemporary sources, but on recognition of the difficulties presented by the major issues. On the last point it is salutary to be reminded that in countries such as Ceylon, where a rapid expansion of population has occurred within the past few decades, there are considerable differences of opinion between informed observers about the relative contribution of malaria control, other medical measures and a rising standard of living, particularly nutrition.8,9 If conclusions concerning the eighteenth century must be largely influenced by prior hypotheses, it is clearly important to decide on what evidence they are to be based. The best evidence, I suggest, is from the time when there is sufficient information to support an interpretation; and the minimum requirements are data concerning birth rate, death rate and cause of death. The birth rate and death rate are needed to assess the contribution of an increase of the one or a decrease of the other to population growth, the issue which has had so much attention in eighteenth-century studies; and cause of death is essential for appraisal of the influences which contributed to the decline of mortality. In England and Wales these minimal data are available from 1838. The problem of extrapolating from the later to the earlier period is in some respects less difficult than it appears to be. For example, if in the light of knowledge of the diseases which declined after 1838 it is concluded that specific measures of preventing or treating disease in the individual made no significant contribution to the reduction of the death rate during the nineteenth century,10 it seems reasonable to conclude that such measures are very unlikely to have been effective a hundred years earlier. Since the introduction of improved sanitation coincided with the decline of the bowel infections in the 1870's10 we can be fairly confident that this was not a significant influence during the eighteenth century. And if a reminder is needed that mortality from a single infection may fluctuate apparently without medical or other intervention, in a period when more important influences are changing the whole pattern of disease, it is provided by experience of scarlet fever in the nineteenth and twentieth centuries. The failure to make full use of nineteenth century evidence before turning to the uncertainties of the earlier period, although regrettable, is understandable. Historians have been particularly interested in the association between population growth and the beginning of the Industrial Revolution, one of the important issues in economic history, and they have been less concerned with the nineteenth century when the relationship seemed more obvious and therefore less challenging. But whether the focus of interest is the eighteenth century, or interpretation of the modern rise of population as a whole, the most promising approach to an understanding of the first phase of population growth is through investigation in the years immediately after registration, when the data are sufficient to raise discussion above the level of speculation. Mortality from this disease was declining rapidly from the time of registration of cause of death and this appears to have been responsible for nearly half of the total reduction of mortality (from all causes) between that time and the end of the nineteenth century. No treatment was effective, and the main issue is the relative importance of a change in the character of the disease and of improvement in the environment.10 There must be uncertainty concerning the acceptability of diagnoses, not only before the discovery of the of infectious disease, but the nineteenth century because of the limitations of methods of It is particularly important to decide whether the reduction of mortality from can be attributed to changes in in a of deaths from this to other this should no to the relationship of and the attention to it in the that it has been a of by some economic The significance attributed to the disappearance of is an example of the failure to distinguish between the changing pattern of infectious disease and the of explanation which must be for the beginning of the unprecedented modern rise of This is largely a for the demographer but there is one issue on which judgement is influenced by with contemporary medical evidence. No one with this evidence I believe, be in any doubt that mortality due to infectious disease with birth There be no of the character of early data when without to later medical evidence than the by a demographer that this association is not by a of in between the and nineteenth It is significant that the that this contributed to of the disease, and even to the total decline of mortality and rise of population in the eighteenth century, has not been by medical but has been by some of the best informed them. This will be to later and is only as an example of a medical question which has been are the medical issues which arise in investigation of the most important problem in historical the explanation of the modern rise of It seems remarkable that so far they have had attention from medical historians, but interpretation of the decline of mortality has not been a of medical history in the that interpretation of population growth has been a of economic have been interested in the behaviour of individual infectious diseases and a considerable is concerned with for the decline of mortality from smallpox, scarlet and other But there have been few to assess the contribution of medical and other influences to the of mortality as a whole, or the between mortality and growth of And in so far as such questions have been there has been an to very different the of of the of the focus of interest on the eighteenth century has been the attention to the birth rate when rate is the is to which are as difficult to support conclusively as they are to this discussion may be to economic historians, in to investigation of the for the modern rise of population it is of importance to the question what disturbed either rate. For if the first phase of the modern rise cannot be attributed to medical measures or to change in the this is the which from of post-registration evidence is that the standard of in the eighteenth century, whether its most significant was an increase in the birth rate or a decrease in the death rate. This is not to that discussion at this on the it to a more appraisal of the of the which and on births and the above I consider in the for the rise of population after and before The the data concerning birth rate, death rate and population in England and Wales from the when put them beyond serious It that an of births deaths was established before registration and has the The birth rate high when it to mortality was fairly about the same time when it too to The growth of population from 1838 was clearly due to the of births deaths established before and after registration, and to the decline of mortality from the which to some for a declining birth rate. The main is to for the reduction of mortality in the nineteenth century, and in the light of the conclusions to the between birth rate and death rate at the time of Data from concerning birth rate, death rate and population in England and The data on cause of available only for Britain from so early a are for of these problems. The decline of mortality between and was to the infections and and that diseases or groups of diseases responsible for for a less than a and fever for about a scarlet fever for a and for nearly a and for a of for the changes in disease or disease and if of a hypothesis based on the is one of the most important medical It has not had the attention it and that the for disease can be considered specific medical measures of preventing or treating disease in the a decline of mortality not to medical or analogous to that which must have contributed history to the changing pattern of infectious and improvement in the The last a of influences but at the it is to them the same the diseases which only was influenced by specific medical measures and even if the whole of its decline is attributed to it can for only a of the total reduction of mortality. fever is the example of an whose a period, apparently of medical or other intervention, and its decline can be attributed confidently to the Since the reduction of mortality from bowel infections in the when to make its on and there is also no serious doubt that it was due to improved In the of is not from in before this explanation may not be but for the groups as a whole and and and it seems The is in the rapid and decline of mortality from It occurred from the time of registration almost certainly at before the reduction of mortality from the other main The decline was not due to which did not become effective after the and and concluded that it was due to a rising standard of living, particularly of for not as more change in the disease, the explanation by some because so a reduction of mortality would be unlikely to in this in a population to the disease for and because movements of population from to too to a decrease in the it is that the population of Britain had not been to the it is to be confident about so an one of the most important in medical history, which In of the conclusions in of of the main diseases it was that in of relative importance the influences responsible for the reduction of mortality in the half of the nineteenth century a rising standard of living, of which the most significant was improved for the decline of less certainly and to a of particularly improved and by for the decline of the and and a in the relationship between infectious and for the decline of mortality from scarlet fever and may have contributed to that from and The influence of specific or treatment of disease in the individual was to and made contribution to the total reduction of the death rate. it to be if not in at about the main of this There are for that specific medical measures contributed the reduction of mortality was due to the decline of infectious was the only infection on which medical measures had an and only about a twentieth of the total reduction of mortality between 1838 and was due to the decline of It is not to be equally confident about the relative importance of influences rising standard of and the more specific and decline of But there is to that an in the standard of living, to have occurred by the contributed to the reduction of mortality from and that measures responsible for the decline of mortality from the bowel infections which coincided with in and while it is to assess precisely the contribution of change in the infectious disease, the evidence that other important influences at and the of a explanation for so a reduction of to the main of the In this no will be made to it beyond although I have that for the whole period from 1838 the the in time of the main influences is also the of a rising standard of living, at from improved sanitation from about and and treatment of disease in the with the of against from the of the twentieth century. In investigation of for the growth of population in the eighteenth century there are main or more of to be medical measures of preventing or treating disease in the to a decline of a reduction of and in the whether to an increase of the birth rate or decrease of the death rate. It is to of other influences on population growth, for example a reduction of the birth rate such as occurred in or a increase in but to have contributed to the rise of population in eighteenth-century In the discussion which no will be made about the or of birth rate or death rate, and an interpretation will be in the light of conclusions from the nineteenth century. If it is accepted that with one but not or treatment of disease in the individual was in mortality in the nineteenth century, it would to that they can have had no significant influence on the a century earlier. there is to that some kinds of medical for example expansion of with the of the of a to the of most medical the that inoculation against made a on mortality in the eighteenth makes it to whether this was a remarkable early It is to the history and methods of inoculation in Britain which have been in and it will to that it was a which no one would to use without knowledge of its of or The difficulties of medical issues by on eighteenth-century evidence are more than in the differences of opinion concerning the of inoculation and its effectiveness in preventing It is that the was and that it was that it and that it is to have contributed to the of the The of inoculation is a for but in the of evidence, of its effectiveness should be based on and experience of the disease. an economic historian has not to this issue with a The of those know the disease is that mortality in the eighteenth century was not by it is in with experience of nearly a hundred years of investigation there are a of which against some infectious they been available and in the eighteenth century, even in the of other influences it is that they would have to a reduction of mortality from the specific infections and one or for example have had a on total mortality. But it is most unlikely that any of them would have had an so and as to the increase of population in the eighteenth century. This on not of the effectiveness of but of the contribution of any single infection to total mortality a considerable period. even if very are made about the and effectiveness of it cannot for the rise of population which had occurred before the time of registration, when other influences with a rising standard of certainly It is but somewhat to a decline of mortality as if it was not influenced by medical or other measures such as in the The relationship between an and its is clearly not of the in which they are a distinction should be made between the changes which occurred a to an increase and to a decrease in and those which have been with the reduction of mortality during the past centuries. For the there must be a more specific In the post-registration period it was to consider the significance of change in the character of the individual diseases which contributed to the total decline of mortality. This cannot be before 1838 when cause of death is unknown, and we must rely on a judgement of by knowledge of the nineteenth century. The are the few to of decline of if it occurred before registration, would have been due to a reduction of infectious causes of death. The relationship between and is but the rate of change is very different for different effective medical or other intervention, any considerable period some deaths from infections must have some and fairly There is therefore no to question that one or more infections may have declined in the eighteenth century as did scarlet fever in the nineteenth and other in previous centuries. If it is accepted that medical measures had no significant on mortality before registration, without knowledge of cause of death we must for the rise of population be attributed to no answer can be it seems that this can the unprecedented increase before if some reduction in mortality in the early years of the eighteenth century is analogous to that which occurred in previous before its end the modern rise of population had begun. continuity and coincidence with the Agricultural and Industrial all and it cannot be by a decline of mortality which was of medical or other are therefore with the that the rise of population was with the changes in of which occurred in the eighteenth and early nineteenth centuries. this it will be to to the that eighteenth-century population growth can be by the disappearance of in the of smallpox, the data are and it as well as to in a of mortality whose was centuries. On medical it is also difficult to that changes in mortality (from all causes) and population growth can be attributed to the behaviour of a single disease. But even if had the significance for its decline must be the It was certainly not due to or treatment of the disease in the If it occurred it may have contributed to population growth in the early eighteenth century but cannot be accepted as the main for the first phase of the modern And if declined because of the explanation is with the interpretation which The that a rising standard of was the most important for the reduction of mortality after registration was by of the disease which and was with the fairly opinion of economic historians that by this time had The fact that for after cause of death was first the most was a decline of mortality from made it to and to that the most explanation for its decline was a This explanation was with what is know about the behaviour of the disease and the of and registration the for in the as the explanation for a rising population are somewhat The is after of the measures and and cannot be by of individual causes of death. some economic historians not that on improved in the eighteenth and early nineteenth and they have about the interpretation on this In a of the and concluded as would probably be for medical to to beyond a It is that in the light of an of the evidence after registration, it seems most reasonable to attribute the rise of population which had occurred before that time to improvement in the For the of a interpretation it is not and it may be possible, to the of the or to state a time from which it can confidently be to have begun. But the fact that the population had in a period before doubt that it was well established before the when economic historians are that the standard of had There are for that this was Data to by in his to the in that the explanation for the rising standard of should be in the in He population of England and had to On these the population had itself in years and even if no is made for an improved standard of living, it is that England during the same period had of that by the end of the had and it was not the that from to make a significant This on the importance of is not only with the explanation for the decline of mortality in the years after it is also in with more conclusions concerning the requirements for There are four more of and only the first has been so as to have a on numbers and The was by of all is to increase beyond the prepared for and the eighteenth century any in rapidly by The to which and to support a population, which was by the reduction of mortality But in and on an fairly these would have been by numbers if the decline of the birth rate from had not population growth sufficient control, in to the of a but at to a change in unique in This interpretation of the modern rise and of population in Britain the on improved from or of influences in the by measures from and of numbers by a declining birth rate from about the same It is not that these precisely in the years The in of introduction of a there may well have been some in as there in during the eighteenth and and that measures not for the first time in the more there periods in history when other influences may have been more important than in at of for example in England for many and if and of death from was probably much greater than from in of the population as a whole any considerable period the seems and while the sanitation and birth not unique in they in the and which to introduction and continuity in the eighteenth and nineteenth centuries. This interpretation of population growth largely on judgement of medical the effectiveness of treatment during the eighteenth and nineteenth the for the decline of mortality from scarlet fever above the of inoculation against and the of a reduction of total mortality as a of change in a of infectious disease or of a single disease such as issues are focus by investigation of the modern rise of population, a which has had the attention of economic historians and but so far to any of medical historians have largely this or have enquiry to individual the problem of population growth what is the most important questions in medical history, the for the of during the past centuries.