The number of diseases that I can specify as exhibiting such modifications to any noticeable extent is therefore extremely limited. They are, moreover, diseases characterized by varied and extreme structural changes of the cutaneous tissues, so that a comparison of the appearances presented as they occur here and elsewhere, is easy. The most conspicuous example of such is undoubtedly lupus vulgaris. We have already seen that it occurs far less commonly here than in Europe, and it may be that the same law governs its course as well as prevalence. At all events, I think there can be no question that we do not see cases here which approach those so frequently met with in foreign clinics in severity of the destructive process, or in extent of the surface affected. Such at least is my own experience, and I have no reason to offer in explanation of the fact. It might seem that it required several generations of accumulated malnutrition or more positive constitutional evils to effect such eventual disorders of cutaneous structure, and that on this account lupus prevailed more abundantly and in its worst forms where poverty and bodily misery were more common than with us; but I do not think that the history of individual cases amongst us warrants any such conclusion. I wish I could add that I have found a corresponding benignity of type in its disposition to yield more readily to treatment, but corresponding classes of cases have in my experience exhibited the same obduracy to remedies here as in Europe, and perhaps the same tendency to relapse.

The same statements may be made with truth, too, in my opinion, of the cutaneous syphilides, especially their later manifestations. We rarely, if ever, see here cases of so grave a type as in European hospitals. There seems to be a resistance to the destructive force of the disease, on the part of the skin, which tends to prevent the formation of the worst lesions within its tissues.

Leprosy, too, seems to feel the mitigating effect of some local influence within our borders. In Trecadie it has kept up a lingering existence for many years. With regard to its character among our Norwegian immigrants at the West, at present, I regret that I have no definite information to impart; Prof. Boeck expressed the opinion, after his visit to them a few years ago, that the disease seemed to be partially controlled; its course retarded to some extent by their change of residence. Whether the interesting observations made by him while amongst them are best interpreted under the theory of contagion or hereditability, is not within the province of this paper to consider. As to the character of the disease, as it occurs in our southern States, I am not informed.

Indeed, the best use that I can make of my conspicuous want of knowledge upon this and other points which should be considered under this division of our subject, is to exhibit it frankly as an illustration of what, I fear, may be a too common state of ignorance on our part, and to indicate how much definite information is yet to be acquired before we can intelligently discuss it. Finally, I may add that no one can be so fully aware as myself of the incompleteness of this paper in all respects, and to how unsatisfactory an extent it fails to answer the questions it proposes. I offer it merely as an introductory sketch, or skeleton chart, to show in what directions we may best carry out the investigations which may eventually lead to the full solution of the subject.

The following conclusions seem to be warranted by the data above presented:

I. Certain obscure affections, the etiology of which is little, if at all, understood, even in those parts of Europe to which they are mostly con

fined, may be regarded as practically non-existent amongst us. prurigo, pellagra, and lichen exudativus ruber.

Such are

II. Certain diseases, directly connected with and dependent upon poverty and habits of personal uncleanliness, are less prevalent in the United States than in those parts of Europe of which we have sufficient statistical information for comparison. Examples of this class are the animal parasitic affections especially.

III. Some cutaneous affections of grave character, which are dependent upon or a part of serious constitutional disorders, are of less frequent occurrence and of milder type amongst us than in Europe in general, or those parts of it where they are endemic. Lupus, the syphilodermata (?), and leprosy are the most marked instances of this class.

IV. Certain disorders of the skin, especially those of its glandular systems, and those connected more immediately with its nervous system, are apparently more prevalent with us than in Europe. The most notable examples of the former are seborrhea, acne, and possibly the heat rashes; of the latter, herpes, urticaria, and pruritus.

DISCUSSION ON DR. JAMES C. WHITE'S PAPER.

After the reading of the preceding paper, Dr. Louis A. DUHRING, of Philadelphia, said:-The subject treated of in the paper just read is one of great interest, and the statistics contained in it show that there is a marked discrepancy in the prevalence of skin diseases in the three great eastern cities of this country, Philadelphia, New York, and Boston. How to account for these differences is a difficult problem, and, on account of these differences, Dr. White's conclusions should, it seems to me, be taken with reserve. The precise meaning of some of the terms employed should also be given with more particularity; for instance, morphæa is a name susceptible of several meanings. Dr. L. DUNCAN BULKLEY, of New York, said:-American statistics are not as complete as could be desired. Morphæa is undoubtedly more frequent than it is represented to be in the tables of Dr. White's paper. I have myself seen it in a number of cases. I observe that no cases of prurigo are mentioned in the paper. Heretofore, I have only reported cases observed at hospitals and dispensaries, and have not reported those of my private practice. I have had two cases of prurigo under my own observation in this country. I also believe that, in the types of diseases of a congestive character, there is a marked difference between this country and Europe. I have in New York repeatedly tried Hebra's treatment for this class of cases, without success. I am of opinion that in these diseases, as met with in the United States, there is the general characteristic of nervousness, so peculiar to the American people, which requires a treatment very different from that taught in the schools of Europe. American physicians are discovering this every day; they are becoming more familiar with American characteristics as they grow older, and are finding it profitable to forget much that they learned in the old world.

Dr. DUHRING said :—I have brought up the subject of morphæa in order to ascertain the views of Dr. White on that disease. Dr. White and Dr. Bulkley evidently understand it as Mr. Wilson has described it; whereas I think that Mr. Wilson has so confounded it that no one could recognize it from his definition as a distinctive disease. Mr. Wilson confounds the old morphes of leprosy with the modern morphæa. I have discarded the definition of Wilson, and also that of Kaposi, and have from experience adopted the view to which Dr. Fox has inclined. Morphæa should be entirely disconnected from leprosy. I have seen three cases of it, at a clinic in London, and five in this country. As I understand the disease, its manifestations are of two kinds; the first being the large or small yellowish circumscribed patch upon the skin, like

a piece of fat or lard, in appearance resembling the well-known macular form of leprosy, with which, however, it has no connection. Another form entitled to the name of morphæa is the keloid so accurately described by Dr. Addison. I have seen four cases of this disease in this country. It is an extremely complex affection, requiring great detail and particularity in its description. I have seen all the symptoms encountered in both forms of the disease in one patient; I have seen the macular patches from the size of a pin's head to that of a hand with those numerous symptoms of the so-called keloid of Addison. I have also seen the macular manifestations, accompanied by reddish or purplish streaks and striæ atrophicæ, and, moreover, band-like cicatriform lesions. In a paper recently prepared by me, I have tried to give an accurate description of the disease, but to attempt it here would occupy too much time. Dr. BULKLEY said:-I would designate as morphæa just what Dr. Duhring has described, and, with due deference to Dr. Duliring, would say that Wilson gives a similar description.

Dr. DUHRING said:-Partial atrophy of the face should not be confounded with morphæa, though it closely resembles the cicatriform form of the disease. The subject is a very complicated one, and the clearest distinctions should be made between the old morphæa of leprosy, the macular and cicatriform varieties of the disease now designated morphæa, and unilateral atrophy of the face. Dr. WHITE said:-I had a case which began with the round form of morphæa. It was sent to England where Mr. Wilson saw it and called it morphæa; then to Vienna where Hebra called it Addison's keloid; and, finally, returned to this country and resulted in time in atrophy of the skin. In the paper before the Section the word has been used in all the looseness of meaning requisite to cover the variety of forms assumed by the disease.

Dr. DUHRING said:-I have seen the case referred to by Dr. White, and I would call it unilateral atrophy of the face. The lesions are not confined to the skin, but extend deeper and affect even the muscular tissues and bone substance. In one case of unilateral atrophy of the face which I have observed for eight years, the tongue and roof of the mouth have dwindled upon one side to only half the normal size.

Dr. BULKLEY said:-I have seen two such cases, in which the patches, or arrests of development, resembled very much morphæa. I have also within a few days seen a patient who has been put under galvanic treatment and is twothirds or three-fourths cured.

Dr. DUHRING said :—In the reported cases of unilateral atrophy of the face, the disease has tended to increase from year to year, while in those cases of morphea which have come under my observation, the disease has tended to spontaneous recovery; one young lady who has been the subject of a most extensive morphæa, is now nearly cured, the patches upon her body having undergone spontaneous involution; this never occurs in unilateral atrophy of the face.

Dr. WHITE said :-With regard to prurigo, I am well aware that many English writers do not concede that there is such a disease, maintaining that the cases seen in Vienna are but poorly developed diseases of a secondary character, in which the cutaneous lesions follow, and do not antedate, the subjective features.

Dr. BULKLEY said:-I have seen two well-defined cases of prurigo in native Americans. One occurred in a man who, after terrible suffering, died of the disease. The other was the case of a child.

Dr. S. ENGELSTED, of Copenhagen, said:-Prurigo is very rare in Copenhagen, but is sometimes met with. It sometimes commences in childhood, and is then incurable. It occurs only in the lowest grades of the population.

Dr. DUHRING said:-I agree with Dr. White, that this is a very rare disease. I have seen but one case in this country (at Boston), that I thought was prurigo; I could not positively say that it was so, for I saw the case only once, but if asked to name it I could call it nothing else. I was forcibly struck with its resemblance to the Austrian prurigo. The whole surface was involved.

While attending the clinic at the Hôpital St. Louis, at Paris, I one day saw a boy who had prurigo. Hardy said that he called the disease "strophulus prurigineuse," but it was undoubtedly the prurigo of Hebra. Hardy said it was obstinate but curable. Evidently it did not, in Paris, take on that aggravated form which is commonly seen in Austria. There is at present, in the Philadelphia Hospital, a case very much resembling prurigo, but I would not so call it. I doubt whether lichen ruber is more common abroad than here. Lichen planus and lichen ruber I regard as one and the same disease, the latter being the more advanced stage of the process; I would ask Dr. White whether, in his experience, he has ever known lichen planus to run into lichen ruber?

Dr. WHITE said :-I have not.

Dr. DUHRING said :—I would ask Dr. Engelsted whether he has ever seen in Copenhagen Hebra's lichen ruber?

Dr. ENGELSTED said:—I have not, but I have seen there lupus vulgaris. Dr. DUHRING said:-Lichen ruber is as rare in Europe as here. I have seen in this city a case of lichen planus which passed into what might be called lichen ruber; it was not so severe as the cases I have seen abroad. Prurigo is a common disease in Austria, but lichen ruber is rare. I must also differ from Dr. White as to the severity of the syphilodermata, which I consider to be as severe in type in this country as in Europe.

Dr. WHITE Said:-Upon this point I have written only from my own obser vations in Boston of the severity of the disease, and have made no comparisons with other cities.

Dr. ARTHUR VAN HARLINGEN, of Philadelphia, said:-I agree with Dr. Duhring that Philadelphia has a pretty fair share of these cases, and that many of them are of a severe type. There are no syphilitic clinics in this city; but, judging from the tables of skin diseases, the proportion of the syphilodermata is large.

Dr. BULKLEY said:-I coincide with Dr. Duhring's opinion that the disease is not less severe here than in Europe.

Dr. DUHRING said:-Many cases have come to my notice undiagnosed and consequently untreated. I can recall half a dozen frightful cases which have come from the country districts untreated. In Vienna the disease is, as a rule, recognized at once and treated, and hence it is checked before it reaches its worst stage. One case which I can recall had been diagnosed as cancer, and so treated for fifteen years.

Dr. BULKLEY said:-I have known five cases of elephantiasis Græcorum ; two died within four or five years; another has been progressing eight or nine years, and another four or five years. Two of these cases came from the southern part of this continent. Those which occurred in native Americans were very severe.

Dr. DUHRING said :-I was not aware that leprosy occurred in this country at all unless it was imported. Before being convinced that it exists endemically, I should like to see a case thoroughly studied by a competent observer and have it carefully reported. The disease occurs in Central America and Mexico, in the Sandwich Islands, and also in California; but not, I think, endemically. I have seen but one case in this country, and that was a Cuban, who acquired it probably in Spain.

Dr. WHITE said :-Prof. Boeck thought that the disease, as found in the Norwegian settlement in this country, had been checked by the change of residence. I have known of one other case, one of the tubercular form of the disease, which resulted fatally in Boston.

Dr. VAN HARLINGEN said:-As to lupus, I think that statistics here show a larger proportion of cases of lupus erythematosus than of lupus vulgaris; in fact, the former may be considered a common disease, whereas the latter is not so frequent.

Dr. DUHRING said :-The American type of lupus vulgaris is much milder than the European.

VERRUGAS, A DISEASE PECULIAR TO PERU.

BY

GEORGE A. WARD, M.D.,

MEDICAL DIRECTOR OF THE OROYA RAILWAY.

[COMMUNICATED BY THE SECRETARY.]

It is, I believe, pretty generally know throughout the world that Peru is engaged in the gigantic enterprise of building a series of railways across the snowy peaks of the Andes, in order to connect the Pacific ports with the head waters of the Amazon; and by this means to establish a shorter communication with Europe, thus avoiding the inconveniences which now result from a long and tiresome sea-voyage, as well as throwing open to the world the untold wealth which exists on the Amazon and its tributaries. This wonderful undertaking, conceded to be the greatest engineering triumph of the century, is due to the energy, skill, and perseverance of Don Enrique Meiggs.

On one of these routes, starting from the Pacific Ocean at the port of Callao; passing through Lima, the capital of Peru; thence up the valley of the river Rimac; and finally crossing the summit of the Andes by means of a tunnel, at an altitude of 15,645 feet above the sea-level, vast obstacles have been encountered, not only in the way of the many natural difficulties to be overcome, but also from many and strange diseases, one of which it is the purpose of this paper to describe; but before doing so, a brief geographical description of the district in which this disease prevails will be proper.

This district lies between altitudes of 3000 and 6500 feet, cases of the disease occasionally originating a few hundred feet higher, though rarely. In and about San Pedro Mamma, 3000 feet above the sea-level, we find arid dry rocks; but on the river banks, wherever water has access, fine pasturage for animals. The banana here grows luxuriantly wherever cultivated; as we gain altitude, we encounter fine groves of oranges, figs, cherimoyer, peaches, guavas, and in fact every variety of tropical fruit except the cocoanut; as well as vegetables familiar to our northern eyes, such as the onion, lettuce, cabbage, etc. At an elevation of 5280 feet, and 46 miles from the sea, the character of the soil changes, as the valley becomes more narrow, the soil sandy and intermixed with granite, the sides of the mountains steep and producing abundantly a variety of cacti, but still susceptible to a high degree of cultivation wherever water can be carried. At an elevation of about 6000 feet, we find the granite in a friable, decomposing condition.

Running through this valley is a rapid mountain stream varying in depth from two to six feet, and fed by springs and the melting snows of the summit. The temperature at the altitude of 3000 feet is mild and equable; as we gain 4000 feet the temperature is increased, and at an altitude of 5280 feet we frequently encounter a temperature of 110° Fahr. in the shade, in the middle of the day, and at night find it sufficiently cool to require a couple of blankets on our beds, the range of