tain practical inconveniences which accompanied it. We should also imagine that were this system generally carried out, although there would be no danger from paralysis of the heart, the danger from asphyxia would still be liable to interfere with the uniform and absolute success of the agent. To meet the various requirements of the case, Dr. Snow introduced an inhaler (invented by Dr. Sibson), which allows of a gradual admixture of air and chloroform vapour, and enables the person giving the chloroform to dilute the vapour to any extent by the adjustment of the valves. The only objection that can be offered to this apparatus is, that patients are apt to take alarm at the use of an unknown instrument, more than at the application of a pocket-handkerchief to their mouth and nostrils. But medical men ought to be aware of the grounds upon which they should seek to overcome such trivial objections, since the question involved is not one of mere convenience, but may be one of life or death. The collection of fatal cases which had occurred up to the time of Dr. Snow's death, and the careful analysis of the symptoms and post-mortem appearances, alone serve to render the work one of great value. We again see a reason for admiring the assiduity of the author, as well as the scientific zeal which induced him carefully to probe the virtues of his favourite remedy in every direction. It was shown by Dr. Glover, as early as 1842, that chloroform destroys the irritability of the hearts of animals in whom it had been injected into the jugular vein. Dr. Snow has found that the direct application of the vapour of chloroform to the heart arrests its action; the suddenness of the fatal issue in most of the persons who have died from the effects of chloroform, the sudden pallor which spreads over the patient, the arrest of the pulse commonly even before respiration has come to a complete standstill, the frequent presence of fatty degeneration of the muscular tissue in the heart, lead to the conclusion that arrest of the heart's action is the cause of death. It is fair to infer that in that case it is due to an overcharge of the vapour in the blood carried back from the lungs to the left side of the organ. But it is impossible to study the cases brought together by Dr. Snow, without arriving at the conclusion, that if death ensues in the majority of cases by paralysis of the heart, spasm of the glottis, asphyxia, and coma, though less frequently, come in for their share in the causation of the fatal issue. It behoves the chloroformist to bear in mind that each of the organs in which the thread of life may be cut deserves watching, but that the greatest danger, the cessation of the heart's action, may prove irretrievable, if at the first outset, as well as during the later stages of inhalation, the blood conveyed to the heart is charged beyond a certain point with the narcotizing vapour. In concluding this brief notice of Dr. Snow's labours, we would once again urge upon the profession at large the importance of studying carefully the results obtained by our laborious and lamented fellow-worker. We shall be glad to find that his mantle has fallen upon some earnest inquirer, whose claims upon our attention shall be based upon a higher merit than the only one of having administered chloroform, or having seen it administered, in so many thousand cases. We may not, for the sake of science or humanity, allow the great achievement of modern medicine to slip from our grasp because some flaws are yet perceived in its structure. Whether by local applications, or by bringing the whole system under a Lethean influence, we succeed in diminishing bodily suffering, we must seek to obtain perfect control over our agent; but we can no more revert to the times when surgical manipulation and the infliction of pain were synonymous. Yet a little more perseverance and a little more patient research, and we may hope to secure anæsthesia without even the comparatively trifling dangers which still surround its production when properly given. But whenever, in the history of medicine, the subject shall be touched upon, the name of Dr. Snow will stand out prominently, and will receive reverential mention. To use the words which we remember to have heard some ten years ago in the Harveian oration delivered in the College of Physicians by Dr. Wilson, he will ever remain " Nix per æthera notus." แ It may be well to suggest the necessity of always carefully examining the valves, to be certain that they act readily; the valves occasionally get disarranged, so that powerful efforts at inspiration become necessary, which may give rise to injurious results. We may refer the reader for further information on the cause of death from chloroform to the experiments of Dr. Faure (Archives Génerales de Medecine, Juin, Juillet, Aout, Sept., Oct., 1858); and of Dr. Chapman (Med. Times and Gazette, Oct. 80, 1858). REVIEW V. 1. Klimatologische Untersuchungen, oder Grundzüge der Klimatologie in ihrer Beziehung auf die Gesundheits-Verhältnisse der Bevölkerungen. Von A. MÜHRY, M.D., &c.-Leipzig und Heidelberg, 1858. 8vo, pp. 816. Climatological Investigations, or Outlines of Climatology in its relation to the Sanitary Condition of the Population in different Countries. By A. MÜHRY, M.D. 2. Hygiene, or Health as depending apon the Conditions of the Atmosphere, Foods and Drinks, Motion and Rest, Sleep and Wakefulness, Secretions, Excretions, and Retentions, Mental Emotions, Clothing, Bathing, &c. By JAMES H. PICKFORD, M.D. -London, 1858. 8vo, pp. 290. “CLIMATE,' in our sense of the word, comprehends all the physico-geographical forces which act perceptibly upon our organs, which are consequently variously distributed throughout the earth, and are possessed of etiological importance. In the more extended sense of the term, it relates to all organic beings, and therefore to the sciences of botany and rural economy; but in the present work it is considered, at least in the first instance, only in reference to the human race." Such is the definition of Climate given by the author of the work whose title stands at the head of this article. It is, of course, principally in a medical point of view that we shall just now have to consider climate; but there are other aspects scarcely less important to the well-informed physician under which the subject may be studied. These may be found ably unfolded by Mr. Buckle* in the second chapter of his recently published and very remarkable work, in which he considers the "influence exercised by physical laws over the organization of society, and over the character of individuals." The physical agents alluded to Mr. Buckle classes under four heads-Climate, Food, Soil, and the General Aspect of Nature. "The word climate, I always," he says, in the narrow and popular sense." Dr Forry and many previous writers make it nearly coincide with "physical geography." "Climate constitutes," says Dr. Forry, "the aggregate of all the external physical circumstances appertaining to each locality in its relation to organic nature." (p. 37, note.) 66 use Mr. Buckle considers climate, food, and soil, not separately, but under the several heads of the effects produced by their united action-one of the earliest and most important of which is through the accumulation of wealth, the creation of an intellectual class, and the consequent increase of knowledge; secondly, the increase of population, and especially of the labouring class, will be modified by the cheapness and abundance, or, on the other hand, by the scarceness and dearness, of the national food. That the abundance or scarcity of food will in a great measure directly depend upon the climate, is self-evident. But in this respect climate will also have an indirect action; for as in hot countries the animal heat is more easily kept up, and as, on the whole, the bodily exertions of their inhabitants are less frequent, and the decay of tissue is consequently less rapid, smaller supplies of both non-azotized and azotized food will be required in the hotter than in the colder regions. But it follows that in colder regions a more highly carbonized diet will be required; and it is a remarkable fact, that highly carbonized food is more costly than food in which comparatively little carbon is found. Moreover, carbonized food being drawn chiefly from the animal world, and being more difficult to obtain than oxidized food, which is derived from the vegetable kingdom, there is for the most part displayed, even in the infancy of society, among those who require the former, a bolder and more adventurous character than is found in nations "whose ordinary nutriment, being highly oxidized, is easily obtained, and, indeed, is supplied to them, by the bounty of Nature, gratuitously and without a struggle" After some further observations on the subject, the author continues:-"We shall now, I trust, be able to dis History of Civilization in England. By Henry Thomas Buckle. London, J. W. Parker & Son, 1857. Vol. i. General Introduction, Chap. 2. cern, with a clearness hitherto unknown, the intimate connexion between the physical and the moral world, the laws by which that connexion is governed, and the reasons why so many ancient civilizations reached a certain stage of development, and then fell away, unable to resist the pressure of nature, or make head against those external obstacles by which their progress was effectually retarded." (p. 63.) The foregoing may suffice to show the importance of climate in the points of view under which it is so ably considered by Mr. Buckle. In now turning to the more medical aspects of the question, we shall place ourselves chiefly under the guidance of Dr. Mühry. This writer commences with the climatology of mountains, in investigating the effects of which upon the human organism the following elements are to be taken into consideration:-1, the diminishing temperature as we ascend; 2, the diminishing density of the atmosphere; 3, the diminishing quantity of watery vapour (with, at a certain height, in consequence of the fall of temperature, an increased amount of precipitated moisture); 4, the increasing force of evaporation. As the surface of the earth between the Equator and the Poles is divided in reference to temperature into three zones, the author distinguishes in mountains three corresponding vertical regions: 1, the lowest or hot region, extending at the Equator from the level of the sea to a height of 3000 feet; 2, the middle or temperate region, reaching at the Equator from 3000 to 12,000 feet; 3, the superior or cold region, extending at the Equator from 12,000 to 16,000 feet.* But as these elevations diminish as we recede from the Equator, though not everywhere with uniformity, it is evident that the conditions of the several zones as to atmospheric pressure, moisture, &c., must vary in different latitudes. In reference to the nosography of mountains, four classes of diseases are to be distinguished: 1, diseases which occur everywhere, and are consequently to be met with here; 2, diseases the distribution of which depends exclusively on temperature; 3, diseases which are to be termed proper mountain diseases; 4, diseases which are absent in these regions. I. Ubiquitous diseases are those which are not limited by temperature, and occur in all three regions-zymotic diseases, small-pox, scarlatina, measles, hooping-cough, catarrh, influenza; also diseases depending upon dyscrasia; tuberculosis (but not pulmonary tubercle), scurvy (?), scrofula, hæmorrhoids, dropsy, furunculosis, anthrax, gangrænescentia (?), carcinoma, helminthiasis, herpes, scabies, strumosis, uro-lithiasis. II. The three vertical regions, as they are above assumed, are characterized by the following distinctive morbid constitutions, so far as these are dependent on temperature; which morbid conditions both afford analogy to the horizontal distribution of disease over the degrees of latitude, and are also confirmed by experience; on this point, however, much is still to be expected from more accurate statistical data. The author enumerates them in detail, that the accuracy of the classification may be tested as opportunity offers. 1. Upper, or cold region, mean temperature from 32° to 41° F. The physiological predisposition is: plethora, the general character is inflammatory, the predominant organic tendency is to the respiratory organs. Diseases of frequent occurrence are: influenza (whether it occurs more frequently, or as often as at lower elevations, is indeed not yet decided), erysipelas, metritis puerperalis (only supposed from analogy), catarrh, pneumonia (these two are designated very severe diseases in elevated situations), croup, trismus neonatorum (these two forms are only conjecturally of frequent occurrence), ophthalmia. Absent diseases are, the three terrestrial miasmatic epidemics: malaria fever (at least it is much rarer and weaker), yellow fever (partly on account of the distance from the sea, partly on account of the temperature), and Indian cholera (at least in the highest region the occurrence of this disease is scarcely possible). Phthisis may here very properly be said to be absent (although probably not in consequence of the temperature, The measurements of heights in Dr. Mühry's book are given in Parisian feet, of which 15 are equivalent to about 16 English feet. A Parisian is to a Prussian foot nearly as 29:80. but of the rarefied condition of the air); dysentery is scarcely to be found so high, neither is hepatitis, nor lepra, nor gangrene, nor are indolent ulcers to be met with. 2. Middle, or temperate region, distinguished into cooler and warmer, namely, from 41° to 54°5 F., and from 54°5 to 72°.5 F. respectively. The physiolgical predisposition is: fluctuation of the phenomena according to the seasons; their character is in winter more inflammatory; in summer it is more torpid: the predominant organic tendency, too, is in winter rather to the respiratory, in summer to the digestive organs, but the difference produced by the seasons is not so great as in the lower region. The more frequent diseases are: typhus, gout, diseases caused by cold, as catarrh, angina (refrigerosen). Absent diseases: the violence of the diseases which characterize the two extreme regions is here less; that is, on the one hand, pneumonia, erysipelas, catarrh ; on the other malaria fever, dysentery, hepatitis, ophthalmic, impetiginous affections, gangrene, indolent ulcers. 3. The lower, or hot region, mean temperature from 72°5 to 81°5 F., presents exactly the class of tropical diseases. Physiological predisposition: the opposite of plethora, blood poor in fibrin and diminished in quantity; the character of the phenomena is permanently torpid or adynamic; the predominant tendency is to the digestive organs, especially to the liver and intestinal canal, also to the spinal marrow and skin. Frequent diseases are: all the three terrestrio-miasmatic affections in an intense degree; hepatitis, dysentery, encephalitis, tetanus, lepra, pachydermia, gangrænescentia, ophthalmias, impetigines. Absent forms: typhus, plague, cretinism; gout and kidney affections are rare. III. Having disposed of the above diseases dependent on temperature, we pass to the peculiar orographic morbid forms, which are determined by the meteoric relations of mountains rather than temperature. Undoubtedly the next most powerful etiological principle is the rarefied condition of the air, then in some measure the state of moisture of the atmosphere, and in connexion with both the increasing force of evaporation. The physiological influence of these causes affects principally the respiration, the circulation, and the evaporation from the skin and lungs. The proper orographic morbid states endemic on all mountains enumerated by the author, are-1. Mountain asthma, the best means of relieving which, after denser air itself, are, rest, the maintenance of warmth; in plethoric patients the abstraction of blood, and coca leaves (erythroxylum coca), with their almost miraculous property of stimulating and strengthening. 2. Dryness and chapping of the skin. 3. Ophthalmia; the dazzling appearance of the snow, increased by the intensity of the light, occasionally produces a sudden attack of conjunctivitis, combined with intolerance of light. 4. Hæmorrhages do not occur with frequency until we reach an elevation of between 17,000 and 20,000 feet. 5. The "Tabardillo" of the Andes possibly comprises encephalitis, pneumonia, and typhus. 6. Goitre and cretinism. At a moderate elevation certain physiological changes take place which are worth mentioning, such as a feeling of lightness and strength, cheerfulness, increased innervation; the digestion is strengthened, sleep is improved, the circulation is excited, the skin becomes more ruddy, slight headache is produced. There is also a diminished susceptibility of the intoxicating effect of spirituous drinks, which is probably connected with the increased cutaneous perspiration. The diseases which diminish or wholly disappear, and are therefore endemically absent in elevated situations, are next enumerated. Traumatic inflammation runs a lighter course; wounds heal better. This is probably owing to the combined influence of the rarefied state and of the dryness of the air; or in other words, to the increased force of evaporation. Indolent ulcers are only exceptionally heard of; dysenteryi s less formidable. The numerous chronic cutaneous affections of hot low countries, from lepra to the impetigines, disappear in elevated regions. 2. But the most important, and possibly the most practically useful, influence of the climate of the higher regions, and which is to be ascribed specially to the rarefied condition of the air, is the decrease and complete absence of tubercles of the lung, pulmo nary phthisis, the diminution of this disease being plainly perceptible at an elevation of 4500 feet. 3. Obesity is rare, probably owing to the strong evaporating power of the atmosphere. 4. Probably from the same cause the renal function is less exercised, and perhaps diabetis and albuminuria will more rarely occur. 5. The psychical influence of mountains on their inhabitants, and still more on visitors, which is in general of an exhilarating character, is not to be left out of view. 6. The diseases which are avoided, especially in the torrid zone, by ascending the adjoining mountains, are numerous: malaria fever, yellow fever, and in a great measure Indian cholera; dysentery, especially in the chronic form, is relieved; dyspepsia, hepatitis; many other diseases are warded off, or cured, and among them, as has already been observed, phthisis. On the contrary, affections. which are endemic in the mountains are equally benefited by a descent to the lower regions, examples of which are found in bronchitis, catarrh, erysipelas, gout, typhus. The author briefly describes the data from which the foregoing deductions have been made. They consist of reports from Cerro de Pasco, a mining town in the Andes, containing at an elevation of 13,600 feet, a population varying from 6000 to 12,000; and from other localities at 14,000, 11,200, 11,000 feet, &c., above the level of the sea. The author states that his is the first attempt to frame a general climatology of mountains, Dr. Lombard's work, 'Des Climats de Montagne,' &c., having been confined almost entirely to the local circumstances of Switzerland; and he enumerates Mexico, Puebla, Santa Fe de Bogotá, Quito, Arequipa, Chuguisaca, Potosi, La Paz, Cerro de Pasco, Cuzco; and in the East Indies, Outacamund, Simla, Landour, Dorjiling, Caboul, and Cashmere, and Erzerum in Armenia, as places where valuable observations might be made. We come now to a very important subject; the absence of phthisis in some districts, and particularly in the rarefied air of elevated regions. The importance of discovering the climates where this disease, which indisputably, next to convulsions in the first weeks of life, occupies the largest place among the causes of mortality of the human race, will be at once apparent. Pulmonary tuberculosis is wanting in no zone, nor is it by any means absent in the torrid zone; in some localities of this region it is even particularly frequent. Consequently the geographical distribution of temperature has no influence on its occurrence, although, as is well known, where the lungs are already diseased, cold, and especially sudden change from warmth to cold, is very injurious; and on the contrary, removal to a higher temperature may act very beneficially: but we are now speaking only of the endemic occurrence of pulmonary consumption. On the other hand, there are 1, certain regions in all zones where phthisis is of rare occurrence, or is almost entirely absent; 2, there is, moreover, the very great probability, we may even say the certainty, of its frequency decreasing as the perpendicular height increases, until it completely disappears. 1. Districts in the several zones which exhibit an exemption from phthisis. Phthisis is said to be very rare in Iceland; in the Feroe Islands it is reported as being rare. We are informed that on the borders of Canada, at Fort Kent, Maine, where the mean temperature is 35°8 F., and where quicksilver freezes in winter, phthisis scarcely ever occurs. In the temperate zone there are three districts remarkable for special immunity from phthisis-namely, Algiers, Egypt, and Syria, and the steppes of the Kirghiz, near Orenburg. We may add that in Marstrand, an island within six or seven miles of the coast of Sweden, consisting of a single rock of granite, mixed with gneiss, pulmonary consumption is scarcely known among the natives of the island, which, from some peculiarities in its climate, has received the name of the Madeira of Sweden; and the disease appears to be remarkably arrested in such phthisical patients as sojourn there during the summer months, viz., from the beginning of July to the end of September.* With respect to the torrid zone in general, it is first of all to be observed that phthisis does not occur less frequently in it than in colder regions. In Senegal, Angola, and Benguela it is rare. The East Indies, with all their insalubrity from hepatitis, dysentery, malaria fever, and cholera, enjoy a remarkable immunity from phthisis. * See Dr. Magnus Huss, Om Sverges Endemiska Sjukdomar. Stockholm, 1852, p. 51. 2 |