steady average of about two and a half times greater; though some of this might be attributed to individual peculiarity, yet the difference seems more than can be accounted for on that supposition, aud may be fairly referred to the effect of climate. The alvine discharges present characters somewhat analogous, which will be noticed below. If a few drops of urine be added carefully to hydrochloric acid in a test tube, a colour varying from deep blue, through different shades of purple, to red, may often be seen along the line of junction. This arises from uroxanthine, or rather its derivatives, uroglaucine and urrhodine, in varying proportions. Nearly every specimen of urine examined for the purpose, whether from sick or well, presented traces of these, though at times the quantity was both larger and more constant. Thus, up to the beginning of 1859, urrhodine particularly attracted attention from its frequency and quantity, but at that time it diminished rather suddenly, and continued scanty in most cases until the early months of the present year (1860). Soon after this diminution cases of fever presented an early and unusual degree of tenderness over the liver, and depth of bilious suffusion, characters they began to lose only in 1860. These colouring matters were not met with in very large quantity at any time, unless hepatic derangement were present, but when that led to deep bilious impregnation of the system, they were never found to be copious. Hippuric acid is another constituent of the urine in Jamaica, which is found in large quantity in both the white and dark races, whether sick or well. I first detected it in August, 1848. I have since examined the urine for it in one hundred and ten instances, and found it in every one. These cases embraced Europeans, and creoles of all colours, and persons who were healthy as well as others who were labouring under different forms of disease. It was found as constantly in the urine of healthy European soldiers stationed at Newcastle, nearly four thousand feet above the sea, as of those who resided in the low ground. Few, if any, of these persons could have taken benzoic acid, unless it were contained in the yams, or other vegetables composing part of their food, but I am not aware that it has ever been detected in these. The quantity of hippuric acid is usually so considerable, that if the urine be concentrated by evaporation over a water-bath to one-eighth of its bulk, then acidulated with hydrochloric acid, and set aside for twenty-four hours, a pretty copious deposit of crystals of hippuric and uric acids will be found on the bottom of the vessel. The crystals are usually in the form of elongated plates, or needles, derived from an oblique rhombic prism, though, by solution in water and slow evaporation, more distinctly prismatic forms are obtained. These crystals presented a brilliant appearance with polarized light; they were sparingly soluble in water, but readily so in alcohol and ether. When dissolved in lime-water, and the fluid allowed to evaporate, many of the varieties of crystals figured by Robin and Verdeil as hippurate of lime (Atlas,* planch xxi. fig. 2) were seen. With polarized light these Traité de Chimie Anatomique et Physiologique. presented a very brilliant yellowish-white colour. These characters sufficiently indicate hippuric acid. The easiest method of determining the presence of this acid in any specimen of urine (supposing it to be present in sufficient quantity) is to place a couple of drops on a slip of glass, and add a drop of hydrochloric acid; the mixture is then allowed to evaporate, when the crystals of hippuric acid may be distinguished, with more or less uric acid, according to circumstances, scattered through the specimen.. Sometimes, however, the specimen remains fluid, though exposed to a dry atmosphere for days; if a drop of nitric acid be added to such, a rapid crystallization in general takes place, and the hippuric acid appears in another form. If a drop of nitric acid be added in the first instance, instead of the hydrochloric, the crystallization presents a different, though very characteristic appearance. As the fluid becomes concentrated, crystals of hippuric acid form at various points round the extreme margin, from whence needle-like prolongations shoot out nearly parallel to the margin, and crystals of nitrate of urea are quickly deposited among them. These extend on either side of the point from which they started, until they meet with those from the neighbouring centres of crystallization, when they stop, leaving a well-defined separation between them; and as the fluid in the centre evaporates, the crystallization extends towards that, the greater part of the solids being deposited round the sides, and the centre being left nearly bare. Needle-like crystals of hippuric acid may be seen on the surface of the mass, with a close resemblance to a bundle of the leafless branches of broom, while the intermixture of that acid and nitrate of urea bears a considerable resemblance to plumes of ostrich feathers. A microscope is necessary for distinguishing these characters; they may be seen with a power of 60, and with one of 100 they are quite distinct. With polarized light the appearance is very brilliant. In every case in which urine was examined for hippuric acid, one or both of these methods was employed, and the quantity was always sufficient to give decided indications of its presence, and often was copious. In the majority of instances, crystals of uric acid were found also, but occasionally none were visible. It was observed in the course of the examinations from which the above facts were obtained, that portions of urine acidulated with hydrochloric acid remained fluid for days, even though the temperature was high and the air dry. This seemed owing to the medicine taken in some instances, but at other times every specimen examined, whether from a healthy or sick individual, and for many weeks in succession, presented the same character. This peculiarity was obviously attributable to the presence of some of the more deliquescent salts, and from its being so general, was in all probability connected with some of those influences called epidemic, of which as yet we know so little. Its mention here may induce others who have the opportunity, to prosecute the investigation. The colour of the alvine discharges is usually considered to be de · rived from bile, and though doubts have been from time to time thrown out as to the accuracy of this opinion, it still maintains its ascendancy. Holland, in his Medical Notes and Reflections' (second edition), suggested that the colour of the discharges from the bowels was much more owing to the secretion of the colon than to the bile. Osborne supposes that the mucous membrane of the intestine can secrete dark bile, though the bile-ducts be obstructed. Frerichs states in his sixth observation, that "The colour of the stools was somewhat brownish, not owing, however, to the admixture of bile-pigment, but, as shown by the microscope, to numerous epithelial cells containing pigment derived from the mucous membrane and glands of the intestine."t The following observation is more to the purpose. A gentleman in Kingston, Jamaica, had an attack of diarrhoea at five A.M., on the morning of the 10th February, 1860. This was followed by much irritation and soreness along the transverse and descending colon, which continued during the day. There was another loose motion about eight A.M., of a deep dark brown colour, like very thin fæculent matter, a portion of which was obtained without admixture with urine. Under the microscope this was found to contain a large quantity of glandular epithelium, either separate or contained in distinct tubecasts; there were a few pieces of the inner husk of wheat, and some of the pulp of fresh figs, eaten the previous day. The epithelial cells, whether separate or in casts, were almost all deeply tinged with a brown colour; no blood globule was seen among them. The colour of the evacuation was altogether owing to the epithelium it contained. These facts are conclusive as to the possibility of colouring matter being obtained from the intestine, and they indicate pretty clearly the extent concerned. If a portion of an ordinary formed fæculent evacuation be examined, it will be found to contain portions of partly digested articles of food, such as muscular fibre, ligamentous substances, starch granules, with quantities of other matters which seem little changed, such as vegetable cells, inner husk of wheat, &c.; besides these, however, a large quantity of granular matter, of glandular epithelium more or less granular, and even of portions of tube-casts filled with a similar epithelium, are to be seen throughout the specimen. The tube-casts are generally in short fragments, and many portions may be detected, some sideways, others presenting an end only. This epithelium and granular matter is all impregnated with a brown pigment, and is usually the only colouring matter to be seen, and nitric acid does not produce in it the characteristic reaction of bile. The colour of the alvine evacuations of the white races who have resided for some years in a warm climate is habitually much darker than in colder countries, and this though the food contain no colouring matter to affect them. On first proceeding to the tropics the change comes on gradually, and perhaps may not be fairly developed for several * Dublin Journal, Feb. 1853. † Frerichs on Diseases of the Liver (Sydenham Society's edition), vol. i. p. 138. years, nor until the individual may have undergone one or more attacks of fever; and, on his return to a cold climate a retrograde change occurs, the colour becoming perceptibly lighter in the course of a few months, though it is probable the change may continue for much longer. It is a matter of common observation, that those portions of the surface which are exposed to the light become in a few years very swarthy in the white races in warm climates; the same is observed to a minor degree in warm weather in temperate climates. In the former, however, residents of some standing often present a change of colour in portions of the surface not exposed to light, if there have been any irritation applied to them; thus, cicatrices of ulcers, parts which have been blistered, or even slight abrasions, become covered with a cuticle of a more or less deep brown, quite distinguishable from that of the neighbouring skin. If a portion of such cuticle be examined microscopically, the colour is found to be owing to numerous dark or blackishbrown pigment granules in the epithelial cells, in nowise distinguishable, save in their being less numerous, from those which give the colour to the skin of the dark races. This tendency to the deposition of pigment in the surface epithelium continues, in persons who have resided long in warm climates, often for years after their return to colder countries. It seems now generally admitted that uramatine and the other dark pigments are derived from the hæmatine of the blood. The facts above detailed show that much more of this is thrown out of the system in a given time in a warm climate than in a colder one, but that the capability of throwing it out is only acquired after a somewhat prolonged residence; and, after a return to the colder climate, the habit is only got rid of gradually, and perhaps never completely. Α Acclimatization consists of such a change in the actions going on in the system as enables the individual to live in any given climate, with less liability to disease, or less chance of being injuriously affected by it when contracted, than on his first immigrating to that climate. profuse excretion of hæmatine is one of these actions, and a very striking, though by no means the only one; yet, while acclimated persons rid the system of this by one or more of the methods described, the more important diseases of those unacclimated generally present it in some form of morbid deposition or discharge. To commence with the black races, they present an extensive outlet for the hæmatine in the pigment-loaded epithelium of the skin; and, so far as my observation goes, when in health, neither their urine nor alvine discharges are nearly so dark as in acclimated Europeans. In sickness, however, these often become much darker, and if long-continued, or if there be much purulent or mucus discharge, the colour of the surface becomes much lighter. On the functions assuming their natural character, or the morbid discharge ceasing, the original depth of colour of the surface soon reappears, from the pigment resuming its natural outlet. On the inhabitant of a temperate climate proceeding to the tropics, neither the urine nor the alvine discharges afford a sufficient outlet at first for the altered hæmatine, and there is usually much more irritation of the skin and feeling of oppression from the sense of heat, even though the individual may live moderately, than he experiences a few years after, when the evacuations are more highly charged with pigment. The more serious diseases of the recent immigrant, too, such as yellow fever and dysentery, are characterized by excessive elimination of the colouring matter of the blood; while in remittent fever the hæmatine is often deposited largely in the spleen and liver, and sometimes in the brain, or elsewhere. In females, the uterus is an organ for the elimination of a material rich in hæmatine. In warm climates they are particularly subject to excessive menstrual discharges and affections of the uterus, of which no satisfactory explanation has been offered hitherto. When yellow fever is prevalent, too, the mortality among women is generally much less than among men; and when the female is affected with tropical fever, every practitioner must have observed that when the menstrual discharge came on, the fever almost always disappeared. The facts detailed in this paper offer so far a reasonable explanation of these peculiarities, though confessedly an incomplete one. I have detailed above some of the results of my tropical experience, and have attempted to deduce from them conclusions bearing on the question of acclimatization, with what success others must determine. Though so much prominence be given to the removal from the system of the products of hæmatine, it must be distinctly understood that that is to be regarded only as one of a series of actions, and in all probability as one of the least important of that series; but being within our cognizance, it was advisable to develope its relations. Should these remarks induce others to follow up the subject of acclimatization, or to use their opportunities to determine the effect of epidemic influences on the system, my object in laying them before the profession will be attained. ART II. Unusual Cases of Poisoning. By FRANCIS OGSTON, M.D., CASE I-Fatal poisoning by lucifer-matches: suicide.-On the morning of the 9th of March, 1858, Margaret McB- a mill-worker in Aberdeen, swallowed, with a suicidal intention, an unascertained quantity of the matter scraped off from the points of lucifer-matches in her apartment. When seen by Dr. Nicol, of the Aberdeen Royal Infirmary, on the evening of the same day, she was suffering from nausea and retchings of watery fluid, and complained of thirst and pain in the epigastrium. There was marked pallor of the face, her extremities were cold, and her pulse was weak and almost imperceptible. Next day, in addition to the above symptoms, she had at times cramps of the legs. The sickness, pain, and vomiting continued with little intermission, without any movement of the bowels, till the 13th, |