diminished proportion; bronchitis, on the other hand, presenting an equivalent increase.

For defects such as intimated the momenclature employed for the registration of deaths is, as just above remarked, chiefly responsible. It has no solid pathological basis; it admits of the registration of the cause of death on the basis of etiology, of symptomatology, of morbid anatomy, and of mere localization, or by the use of general terms expressive of morbid association. Thus, we have numerous deaths set down to atrophy, debility, and want of breast-milk; to asthma and dropsy; to laryngitis, pneumonia, cancer, and hernia; to brain, liver, kidney, uterine or joint disease; and to those widely embracing conditions, privation, premature birth, and childbirth.

But it is deserving special notice, that the results worked out in the valuable paper reviewed contribute to rectify the returns of mortality, and to suggest the true final cause of death concealed under the different appellations employed. This important result follows on instituting comparisons between the various curves figured for the several diseases, and it is one that has not escaped the attention of the writers. When making a special examination of the curves found for diarrhoea, cholera, and dysentery, they remark that they do so

"In order to point out that deaths from other diseases of the digestive organs have curves which closely resemble those of diarrhoea and dysentery, and may be regarded as substantially the same. In other words, they are influenced by weather in the same way, though the degree of the influence may not be so great. Probably this is true of deaths from all such diseases. It is certainly true that there is no marked exception. It is true, for instance, of deaths from jaundice, and still more strikingly true of deaths from tabes mesenterica and enteritis."

In the curves of these maladies no tendency to a winter maximum, such as is uniformly shown by deaths from diseases of the respiratory organs, is noticeable; whilst, on the other hand, they all coincide in having their maximum in July and August, like diarrhoea and dysentery.

Again,

"Deaths from certain causes, not classed as diseases of the digestive organs, also show the diarrhoea curve; for instance, as deaths from thrush, atrophy and debility, and want of breast-milk. . . . . The form taken by their curves would indicate that, among those whose deaths are attributed to these three causes, grave bowel complaints are of frequent occurrence. It will be seen that this points to a new use of these death-curves, since it is possible that they may indicate those organs the disorder of which, in the different assigned causes of death, leads generally to the fatal issue" (p. 241).

We are quite ready to grant that the ultimate cause of death in the mortality assigned to the morbid states referred to is, in most instances, diarrhoea; but we must remark, that the loose terms, thrush, atrophy and debility, and want of breast-milk, convey no actual information, in the majority of cases, of the real pathological changes, or the lesions which are at the bottom of the symptoms designated under those names. They are, indeed, mostly nothing else than terms whereby ignorance of the true morbid state leading to death is hidden. And the same may be said of diarrhoea in regard to a host of the deaths returned as due thereto. But, whatever be the amount of truth in this criticism, it is a clear gain to have the fact made patent by these curves, that the fatal issue is brought about by one common agency, diarrhoea, in several morbid conditions bearing distinct names, which are supposed to represent the true cause of death.

Illustration of the like deductions from the study of the curves may be found by contrasting those for hydrocephalus, teething, convulsions, brain disease, and, though with some limitation, hooping-cough. The examination rather enhances than lessens the value of the diagrams as exponents of the relations of weather to deaths from those assigned causes; but whilst pointing to a greater fatality at one season than another, and to a possible morbid unity among them, it may be taken to show that what one individual will certify as a death from hydrocephalus another will return as one from convulsions, or teething, or brain disease, or hooping-cough, accompanied by convulsions. It is here worthy of remark, in connection with the teachings deducible from these researches, that hooping-cough ranges itself in the series of nervous maladies, and not, as might be presumed, with diseases of the respiratory organs.

Suffocation ranks legitimately as a cause of death, but no relation would suggest itself as subsisting between it and the weather, yet it is made clear that it is commonest in the cold season; and we can find a rational explanation of this in the larger use of fire and gas, in the longer nights, and the prevailing drunkenness of Christmas and the New Year, to which cause the newspapers inform us the deaths of many children are attributable, the children being overlaid by their drunken parents.

We have previously observed that the researches now before us demonstrate, what a practical acquaintance with disease will confirm, that meteorological conditions are chargeable only partially with the production and the termination of disease. They may either concur with or be opposed to other active influences. The same exposure to cold may in one individual develop rheumatism, in another pneumonia or bronchitis, in

another quinsy. The like variety of results follows exposure to heat to a less degree.

Further, the conclusions arrived at by Dr. Mitchell and Mr. Buchan, with regard to zymotic diseases, bespeak a greater or less indifference on the part of those maladies to mere meteorological conditions, and the existence of some agency, probably special to each zymotic. We are ready to admit that the effects of cold weather are more or less distinct in most such maladies; for it is in accord with universal experience that their severity and fatality are aggravated by cold, particularly such of them as expend much of their morbific energy upon the respiratory passages, as for instance measles. for instance measles. Yet, taking this example, we notice that if its curve presents a maximum in December and January, it also shows a secondary maximum at Midsummer. Again, the curve of scarlatina clearly proves that its fatality is regulated by some conditions other than what the thermometer can indicate. Its climax is reached in October and November; it sinks to its average in January, and remains considerably below it until August.

Without seeking further illustrations from among zymotic diseases, we may find another in rheumatism. This disease has its maximum mortality in November and December, and a range above the average until the end of April. Yet though this curve apparently shows it to be a disease of cold weather, we feel compelled to look for other causes of its prevalence than cold, or cold and wet combined. In countries where the cold is more intense but drier than in this country it is less common; and on the other hand, in the hot and dry land of Egypt it is a very frequent and fatal disease.

A strong, probably the strongest inference arrived at in the essay before us is, the apparently direct relation between heat and the mortality from diarrhoea, dysentery, and cholera. Yet even with respect to this phenomenon a wider experience and more intimate inquiries into the production of disease will prove that heat is not the sole morbific agent. If heat occupy the foreground and arrest the attention, there is something in the background not to be overlooked or despised.

The mortality curve does vary in "bowel complaints," not only in its range, but also in respect of the months at which it reaches its maximum and minimum. In the number of the 'Scottish Meteorological Society,' July to October, 1875, previously quoted, Mr. Buchan remarks

"The differences in the rates of mortality from diarrhoea in the different towns are very great, and a comparison of the two extremes, Leicester and Edinburgh, is startling; the figures showing that for every one who dies from diarrhoea in Edinburgh during the summer

months eight die in Leicester from the same disease, in proportion to the population. From the beginning of November to the summer solstice the mortality from diarrhoea is everywhere small, being double, however, in Liverpool and Manchester as compared with London and Portsmouth."

And again, after insisting upon the fact that towns having a lower summer temperature have also a lower ratio of deaths froni diarrhoea, and that there is a rise in the ratio in proportion to the increase of temperature, he is fain to recognise the farther fact that "the rate of increase differs very greatly in different towns," and to perceive that

"This points to other causes than mere weather, particularly the relative temperature and humidity of the place, as determining the absolute mortality. Thus, the summer temperature of Dundee and Perth is nearly the same, and that of Glasgow and Edinburgh is also nearly alike, the excess being rather in favour of Perth and Edinburgh, and yet the diarrhoea mortality of these two towns is respectively less than that of Dundee and Glasgow. It may therefore be assumed that there is something in the topographical, social, or sanitary conditions of Dundee and Glasgow which intensifies the evil effects of hot weather on the health of the people, so as to swell, for instance, the death-rate from diarrhoea at Dundee to double of that of Perth."

The extraordinary mortality from the same disease at Leicester compels the same inference; and, in aiding us to apprehend its cause, we have available the admirable special report on diarrhoea in Leicester by Messrs. Buck and Franklin.1 These gentlemen look upon the disease in that town as having a specific" character and to be due to local causes, and that such causes are to be found in organic emanations. The emanations are developed specially by the agency of heat acting upon a subsoil saturated with sewage, or "water-logged." The greater or less prevalence of the malady in the several parts of the town stands in direct relation with the degree in which such a contaminated or saturated subsoil exists. Neither density of population, nor the construction of the houses, nor unfavorable social conditions, exhibit any direct influence on its production.

Further, when an epidemic prevails the apparent immediate relation between heat and diarrhoea and cholera is very considerably disturbed. The annals of cholera tell us of its ravages in Russia even during the severe winters of that empire; and just lately we have had placed before us some very elaborate inquiries respecting cholera epidemics in the United

1 Report by W. Elgar Buck and George Cooper Franklin, on the 'Epidemic Diarrhoea in Leicester of 1875.' Prosented to the Sanitary Committee.

2 The Cholera Epidemic of 1873 in the United States.' Washington, 1875.

States, which show that in New Orleans, in 1873, the maximum mortality was in May, and the next highest range in April; that in March and June it was about the same and not quite one fifth of that in April; that in July it had nearly reached its end, and that only single deaths occurred in August and afterwards. In other States of the Union the intensity of the disease varied as to the months in which it happened; but it seems to come out clearly that epidemic cholera will pursue its course heedless of seasons, of heat or of cold, though possibly favoured by heat.

And when a cholera epidemic prevails then also do we find diarrhoea to epidemically prevail, and, like cholera, to show itself in places irrespective of its usual concomitant heat. For example, the same American report informs us that diarrhoea prevailed, not only within the area of the cholera epidemic, but at places even remote from it, and that in some such, as in Texas, its destructiveness took place in the middle of winter.

Here we must conclude this lengthened analysis of this essay on weather and mortality, thanking its authors, Dr. Mitchell and Mr. Buchan, for the amount of information they have presented as the fruit of most painstaking, honest, and laborious researches. The essay is not only instructive, but also highly suggestive; and what now is wanting is the carrying out of a course of similar investigations for other large cities, both at home and abroad; the like general plan and the same system of observation being employed, and uniform meteorological investigations diligently made and recorded. J. T. ARLIdge.

VII. Recent Text-books on Obstetrics.1

SINCE the publication of Tyler Smith's Manual,' a book which marked an epoch in obstetric science, no text-book had, until quite recently, appeared in the English language.

11. A System of Midwifery, including the Diseases of Pregnancy and the Puerperal State. By WILLIAM LEISHMAN, M.D., Regius Professor of Midwifery in the University of Glasgow, &c. Second edition, pp. 848. Glasgow, 1876.

2. A Treatise on the Science and Practice of Midwifery. By W. S. PLAYFAIR, M.D., F.R.C.S., Professor of Obstetric Medicine in King's College, &c. In two volumes, pp. 782. London, 1876.

3. Lectures on Obstetric Operations, including the Treatment of Hemorrhage, and forming a Guide to the Management of Difficult Labour. By ROBERT BARNES, M.D. Lond., Obstetric Physician to St. George's Hospital, &c. Third edition, pp. 606. London, 1876.

4. The Student's Guide to the Practice of Midwifery. By D. LLOYD ROBERTS, M.D., M.R.C.P. Lond., Physician to St. Mary's Hospital (Manchester). Pp. 299. London, 1876.

5. A Manual of Midwifery. By ALFRED MEADOWS, M.D., F.R.C.P. Third edition, revised, pp. 496. London, 1876.