VALENTIN has shown its frequency in the middle and southern provinces of France, GOELIS in Vienna, and GHISI in the north of Italy. Sir JAMES M'GRIGOR notices its prevalence-probably in a complicated form, from its occurrence also in adults (§ 25.)—at Bombay, in 1800. According to the information given by JURINE, LENTIN, CHEYNE, and others, we might be led to infer that it has been more common in very modern | times than formerly: the difference may, however, be owing to its having been mistaken for some other affection.

[M. MARX observes that "this disease, which only a few years past was the terror of all parents, when viewed in reference to its peculiar intensity and frequency, may be regarded as a product of recent times--a bad result of our social condition, and the physical education of our youth. The employment of emetics early in the disease has proved how it can be checked with perfect success; and consequently it can no longer be considered as one of the ominous satellites of our times, whatever may be its origin or nature. The men of civilized nations, as they feed better, are more subject to pure inflammation than those of uncivilized, because they are more plethoric and excitable, and in the main undergo greater toils and perils.”—(On the Influence of Civilization on Diseases," 1844.)]

I believe that it has not been so frequently met with during the preceding five years, as it was about twenty or thirty years ago. M. JURINE remarks, that, although the table he has given of the number of cases from 1760 to 1807, shows a nearly progressive increase, yet he has observed, at Geneva, no increase during the last eighteen years preceding the date of his work. The following evidence, nevertheless, would render it evident, that, in some countries at least, croup is more prevalent now than formerly. According to the information given by Dr. COOKSON, a practitioner of forty years' experience in Lancaster had never seen it until 1760. Dr. FRIEDLANDER (Journ. de Montpellier, No. IX. p. 276.), states, that it has become yearly more prevalent in Vienna; and that the physician to the Hospital for Children, who had treated, from 1774 to 1817, nearly 60,000 children, did not meet with a single case in the three first years of his practice, saw it but rarely during the next six years, and yet treated 1665 cases of it in the last five years of this period. Similar facts are also furnished by Dr. GOELIS. Although croup occurs at all seasons of the year, it is most prevalent in those which are cold and moist, or when the alternations of temperatnre are sudden and remarkable. I have observed it more frequently in the months of January, February, March, April, November, and December, especially if east or north-east winds prevail after heavy or continued falls of rain. I believe that the above results are nearly in accordance with those furnished by JURINE, CRAWFORD, MICHAELIS, DOUBLE, and BRICHETEAU.

25. b. The great susceptibility of early age, and the narrowness of the larynx previously to puberty, have generally been supposed to favour the occurrence of croup. M. BLAUD, however, denies that this latter circumstance has any influence in causing it. This is doubtless the case in respect of the production of the disease, but not as regards its severity and danger, both of which it evidently increases. It is rare to meet

with croup until after the child has been weaned: I have, however, seen it in children at the breast, as early as three, four, five, and six months of age; but much more frequently at this age in those who have been brought up by hand; and in a still greater number of instances, at from seven months to upwards of a twelvemonth, in those which have been recently weaned. M. DUGES states, that he met with an instance of it in an infant of a few days old. The age at which the disease is most common is, according to my experience, from one year to nine. But it not infrequently occurs at both an earlier and a later period. VAN BERGEN states, that it is often observed from the age of two to five years inclusive: HOME assigns from fifteen months to twelve years: CRAWFORD mentions some cases from fifteen months to two years, but gives the age of from two to eight as the most common: CHEYNE, from sixteen months to twelve years; SALOMON, from two to five years inclusive; MICHAELIS, from fifteen months to ten years; ZOBEL, from the latter months of suckling to nine years; VIEUSSEUX, from seven months to ten years; BERNARD, from one to six years; BARTHEZ, from two to ten; RUMSEY, till fourteen; and CAILLAU, from eighteen months to eleven years.

[Dr. DEWEES remarks that this complaint is almost altogether confined to the period of childhood, and is most frequent in infancy, on or before the fifth or sixth year: although he has met with it in its most formidable shape in children at the breast, as well as witnessed death from it in the adult. In Philadelphia, during the eight years preceding 1840, 286 deaths are reported from croup, in infants under one year of age; 275 between two and five years; 171 between one and two years; 67 between five and ten years; and twenty-one over ten years of age. HOME states that the earlier the children are weaned, the more liable they are to the disease.}

The foregoing applies only to the simple and uncomplicated disease. When it occurs in a complicated form, or consecutively upon anginous affections, particularly upon inflammation of the pharynx, tonsils, or fauces, or on the exanthematous diseases, it may, and, indeed, occasionally does, occur in adult subjects, and in infants of a more tender age. The cases published by M. Louis, and denominated by him croup in the adult, were instances of the anginous complication. Although the occurrence of uncomplicated croup in adults is very rare, cases have been observed by HoSACK, MITCHELL, MILLS, and LATOUR.

25. c. M. BLAUD and Dr. ALBERS observe that boys more frequently contract the disease than girls, owing to the greater exposure of the former to its exciting causes. This opinion has been opposed by MM. DOUBLE and ROYERCOLLARD; whilst Dr. JURINE states, that of ninety-one cases he treated up to 1808, fifty-four were boys, and thirty-seven girls; and of twentyeight cases which occurred in 1808, eighteen were boys, and ten girls. According to his observation, also, the greater number of cases occurred at the age of two, three, and four years; and next at one, five, and seven. This accords with my own experience, which is further supported by that of GOELIS, who, from 1797 to 1808, treated 252 cases of the disease, of which number 144 were boys, and 108 girls.

27. d. The nervous and sanguine temperaments,