A systematic treatise, historical, etiological, and practical, on the principal diseases of the interior valley of North America, as they appear in the Caucasian, African, Indian, and Esquimaux varieties of its population

Front matter

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Chapter I

FEVER, TOGETHER WITH THE TOPOGRAPHICAL AND CLIMATIC CONDI- TIONS UNDER WHICH IT PREVAILS.

PAGE

Sect. I. Nomenclature. — Variety. — Identity, .... 17

II. Geographical Limits, ...... 18

III. Conditions which impose Geographical Limits, and give unequal

prevalence to Autumnal Fever, .... 23

Chapter VI. Malignant Intermittent Fever

Sect. I. General History, . . . . . .71

II. Symptomatology, ...... 73

III. Pathology and Complications, . . . . .80

IV. Treatment in the Paroxysm, . . . . . 81 V. Treatment in the Intermission, . . . . .89

VI. Conclusion, ....... 94

Chapter X. Pathological Anatomy And Consequences Of Autumnal Fever

Sect. I. Mortality of Autumnal Fever, . . . . .136

II. Condition of the Blood in Autumnal Fever, . . . 137

III. Pathological Anatomy of Intermittent Fever, . . .138

IV. Pathological Anatomy of Remittent Fever, . . . 142 V. Consequences of Autumnal Fever, . ... .150

CONSEQUENCES OF AUTUMNAL FEVER.

Sect. I.

Diseases of the Spleen: General Views,

Chapter II. Local History. — New Orleans

Sect. I. Condition of the city. — Prevalence in, 192

II. Time of commencement. — Prevalence in different years and

months, compared with Autumnal Fever, . . . 196

III. Annals of the Fever at New Orleans, . . . 201

X TABLE OF CONTENTS,

Chapter III. Local History. — Places East And Southeast Of The Delta Of The

MISSISSIPPI.

Sect. I. TheBalize, . . . . . . .211

II. Military posts, . . . . . . 213

III. Civil stations between New Orleans and Mobile. . .213

IV. Bay and City of Mobile, . . . . . 216 V. Pensacola Bay, . . . . . . .225

VI. St. Joseph's, Apalachicola Bay, and Tampa Bay, . . 235

VII. Key West, or Thompson's Island, . . . .235

CHAPTER IY.

LOCAL HISTORY. — PLACES TO THE WESTWARD AND NORTHWEST OF

NEW ORLEANS, . . . 236

Chapter X. Treatment

Sect. I. Self-limitation —Prevention. . . . . .321

TABLE OF CONTENTS. XI

Sect. II. Remedies for the first and second stages, . . . 322 III. Remedies in the third stage, ..... 343

MISCELLANEOUS OBSERVATIONS.

Sect. I. Mortality, . . . . . . . 351

II. Comparison of Yellow Fever with Autumnal Fever, . .353

Chapter I. Introduction. — General Epidemic. — Typhous Constitution

Sect. I. Introduction, ....... 358

II. A general Typhous Epidemic Constitution, . . . 361

Chapter II

LOCAL HISTORIES OF OUR CONTINUED OR TYPHOUS FEVERS. — SOUTHERN BASIN, APALACHIAN MOUNTAIN REGION.

Sect. I. Sub-epidemic and Sporadic Visitations, . . . 368

II. Sub-epidemic at Elliottsville, New York. . . .369

III. Sub-epidemic at Parisburg, Virginia, . . . 370

IV. Sub-epidemics in Buncombe County, North Carolina, . . 373 V. In the Sub-Alpine parts of East Tennessee. . . . 377

Chapter III

LOCAL HISTORIES OF TYPHOUS FEVERS IN THE SOUTHERN BASIN, CON- TINUED J IN PENNSYLVANIA, OHIO, INDIANA, AND ILLINOIS.

Sect. I. In and around Uniontown, Pennsylvania, . . . 378

II. In Washington and the surrounding country, . . 380

III. In and around Pittsburg, . . . . . .382

IV. In Trumbull and adjoining counties. . . . 383

V. In Belmont and adjoining counties, .... 385 VI. In Greene County, Ohio, ..... 390

VII. In and around Lane Theological Seminary, . . . 392

VIII. Indiana and Illinois, ...... 399

Xll TABLE OF CONTENTS.

Chapter IV. Local Histories Of Typhous Fevers; Southern Basin, Kentucky

Sect. I. In Bourbon County, ...... 400

II. In Scott County, ...... 402

III. In Oldham County, . . . . . .407

Chapter V

LOCAL HISTORIES OF THE TYPHOUS FEVERS OF THE SOUTHERN BASIN CONTINUED. — IN TENNESSEE.

Sect. I. In Smith County, . . . . . . 410

Chapter VI

LOCAL HISTORY OF TYPHOUS FEVERS OF THE SOUTHERN BASIN IN ALABAMA AND MISSISSIPPI.

Sect. I. In North Alabama, . . . . . .412

II. In Maury County, . . . . . . 413

III. In Benton County, South Alabama, . . . .415

IV. Further South. — In and around Dallas County, . . 418 V. In Mississippi, Carroll County, ..... 420

VI. Epidemic Typhous Fever in New Mexico, . . . 421

Chapter X

etiological generalizations continued j sporadic and epidemic prevalence; contagious propagation.

Sect. I. Sporadic Typhous, Primary and Secondary, . . . 452

II. Contagious Propagation, ..... 454

III. Local or Spontaneous Origin of Epidemic Typhous, . . 457

IV. Connection between Contagion aud Local Origin, . . - 462

CLASSIFICATION OF CONTINUED FEVERS, . . 464

Chapter XV. Treatment Of Typhous Fevers

Sect. I. Difficulties, Uncertainties, and Failures, . . . 508

II. Treatment in the Forming Stage, . .... 511

III. Treatment of the earlier periods of the Stage of Excitement, 514

IV. Treatment of the early part of the Stage of Excitement, . .516 V. Treatment of the more advanced and final stages of the Typhous

VI. Treatment in the Final Stages, . . . . 543

VII. Care of the Patient and his Chamber in the Final Stage, . 550

Chapter XVI

RELATIONS OF TYPHOUS FEVERS WITH YELLOW, REMITTENT, AND OTHER FEBRILE DISEASES; SECONDARY TYPHOUS; TYPHOID STAGE.

Sect. I. Yellow and Typhous Fever; Ictero-Typhous, . . . 554

II. Remittent, Autumnal, and Typhous Fevers, . . . 556

III. Treatment of Secondary, or Remitto-Typhous Fevers, . . 559

IV. Typhous complication with various other diseases, . . 560

Chapter IX. Erysipelas. — Introductory

Sect. I. Sporadic Erysipelas, . . . . . 619

II. Epidemic Erysipelas. — Chronology, geography, and contagion, . 622

III. Epidemic Erysipelas continued : Symptoms, . . 630

IV. Epidemic Erysipelas, continued: Pathology, . . . 636 V. Epidemic Erysipelas, continued : Treatment, . . 638

Chapter I. Comparison With The Previous Groups. — Classification

Sect. I. Comparisons and contrasts. ..... 647

II. Classification, . . . . . . . 651

Chapter II

ETIOLOGY OF THE PHLOGISTIC FEVERS. — PREDISPOSING AND MODIFYING CAUSES. — INTRODUCTION.

Sect. I. Temperament, individual and' national. — Age. — Sex, . . 653

XVI TABLE OF CONTENTS.

Sect. III. Diets, drinks, and dress, ..... 658

IV. Occupations, casualties, mental cultivation. — Passions, . 661

V. Pathological and modifying causes, .... 664 VI. Causes which produce specific phlegmasia?, . . 657

Chapter III

RISE AND ESTABLISHMENT OF THE SIMPLE OR COMMON PHLEGMASIA, AND STATE OF THE BLOOD IN THEM.

Sect. I. Of their rise and establishment, . . . . 669

II. Condition of the Blood in phlegmasia?, . . . 673

III. Speculations on the production of Hyperinosis, . . . 679

Chapter VII. N

PHLEGMASIA OF THE CENTRAL ORGANS OF INNERVATION, BRAIN, AND SPINAL CORD, WITH THEIR MEMBRANES.

Sect. I. Prevalence and Causes, . . . . . .713

II. Classification and Diagnosis, . . . . . 715

III. Pathology and Pathological Lesions, .... 722

IV. Prevention and cure of Cerebro-meningitis, . . 725

Chapter VIII

INFLAMMATION OF THE NERVOUS CENTRES CONTINUED I TUBERCULAR ENCEPHALITIS. — HYDROCEPHALUS. . .735

TABLE OP CONTENTS.

Chapter IX

INFLAMMATIONS OF THE NERVOUS CENTRES.— BRAIN AND SPINAL MAR- ROW CONTINUED. MYELITIS AND CEREBRO-MYELITIS.

Sect. I. Sporadic Myelitis. — Parenchymal and meningeal, . . 745

II. Epidemic cerebro-spinal meningitis, .... 751

Chapter X

INFLAMMATIONS OF THE ORGANS OF MOTION, AND OF SPECIAL SENSE. RHEUMATISM. — OPHTHALMIA.

Sect. I. Rheumatism, ....... 764

PHLEGMASIA OF THE RESPIRATORY ORGANS. — ETIOLOGY.

Introduction, ........ 787

Sect. I. Climatic, geographical, and hydrographical causes, . . 787

II. Miscellaneous causes of Pulmonary Inflammation, . 799

Chapter XII. Mucous Inflammations Of The Respiratory Organs. — Catarrh

Sect. I. Endemic Catarrh, ...... 807

II. Influenza, or Exotic Epidemic Catarrh, . . . 809

III. Acute Laryngitis, . . . . . . .810

IV. Chronic Laryngitis. — Diseases of public speakers. — Clergyman's

sore throat, . . . . . . 815

V. Laryngo-Trachitis, Cynanche Trachealis, or Croup, . .819

Chapter XVIII. Tubercular Pneumonitis Or Phthisis Pulmonalis — Etiology And

PROPHYLAXIS.

Introduction, ........ 883

Sect. I. Relations between Climate and the Consumptive or Tubercular

II. Miscellaneous external causes which originate or promote a

Tubercular Diathesis. ..... 902

III. Pathological causes of a Tubercular Diathesis. — Infirmities of

Parents. — Contagion. — Hereditary Transmission, . .910

TABLE OF CONTENT^. XIX

Chapter XIX

TUBERCULAR PNEUMONITIS CONTINUED : DIAGNOSIS OF THE EARLY STAGES^ PATHOLOGY AND TREATMENT.

Sect. I. Early distinctive symptoms and signs of Phthisis, . .921

II. Pathology and progress of Phthisis, .... 929

III. Treatment of Phthisis, . . ... . .937

Chapter XX. Cardiac Inflammations

Sect. I. Introduction, ....... 945

II. Classification and general symptoms of Cardiac Inflammations, 946

III. Peculiar symptoms and pathological characters of Pericarditis, . 951

IV. Endocarditis: symptoms and pathological characters, . 953 V. Symptoms and effects of Carditis, .... 955

VI. Causes of Cardiac Inflammation, .... 958

VII. Sequelee of Cardiac Inflammation, .... 964

VIII. Cure of Cardiac Inflammation, .... 965

THE

PRINCIPAL DISEASES

OF THE

INTERIOR VALLEY OF NORTH AMERICA.

5600k Sbttittib.

FEBRILE DISEASES

Chapter I. Nomenclature, Varieties, And Geographical Limits Of Autumnal

FEVER, TOGETHER WITH THE TOPOGRAPHICAL AND CLIMATIC

CONDITIONS UNDER WHICH IT PREVAILS.

Section I. Nomenclature. — Variety. — Identity

I. Nomenclature. — In different parts of the Interior Valley, the fevers, which we are about to study, are known under the names — autumnal, bilious, intermittent, remittent, congestive, miasmatic, malarial, marsh, malignant, chill-fever, ague, fever and ague, dumb ague, and lastly, the Fever. So great a variety of names suggests two facts : first, diversity of type ; second, wide geographical range of prevalence. I shall use the epithet autumnal, as involving no etiological or pathological hypothesis; and at the same time, including every modification; but, in speaking of diversities, other terms will find their appropriate places.

II. Variety and Identity. — The varieties of autumnal fever are numerous, and often seem widely separated. Thus, the difference in phenomena between a simple tertian and an inflammatory or a malignant remittent, is greater than the difference between measles and scarlatina ; in some years nearly all the cases that occur are intermittent, in others remittent ; finally, although the former seem to be but mild grades of the latter, they often prove suddenly fatal ; and, that too, without assuming a remittent type. Nevertheless, all the varieties must be regarded as making but a single species ; as appears from the following facts : First. They prevail at the same times and in the same places. Second. Under much variety of aspect, they possess many deep-seated analogies and identities. Third. They frequently change from one type to the other. Thus an intermittent turns into a remittent, and the latter, assuming the type of the former, is often seen to become, first, a quotidian, then a tertian, and finally, a quartan. A simple intermittent may, in the third or fourth paroxysm, take on the character of a fatal congestive ; and that which begins with an aspect of malignity, sometimes emerges into simplicity and mildness. Fourth. Vernal agues attack those who in autumn had suffered under remittent fever, not less than those who had experienced the intermittent form. Fifth. The sequelae of all the varieties are almost identical. Sixth. The same treatment with certain modifications, is applicable to the whole. Thus they are manifestly the offspring of the same specific, remote cause ; and when no particular variety is in view, may be designated by one epithet.

Section II. Geographical Limits

Being an endemic of all hot climates we need not look to the shores of the G-ulf of Mexico for a southern limit to our autumnal fever. Its base is, in fact, within the tropics ; and prevailing, of course, in Havana and Vera Cruz, it is found wherever there are inhabitants, on the northern coasts of the Gulf, between those two cities. In ascending all the rivers which discharge their waters into the northern arc of that closed sea, from Cape Florida round to the Panuco River, it is still met with ; and, sometimes, as we shall hereafter see, from the influence of local causes, displays greater prevalence and malignity, than it shows further south and on a lower level.

In every other direction than the south, this endemic has its geographical limits. To the east, its barrier is the Appalachian Mountains, into the very gorges of which, however, it ascends by the valleys which penetrate their flanks. But as that chain is not found south of the thirty-third degree of latitude, it has, below that parallel, no eastern limit but the Atlantic Ocean. To the southwest the Cordilleras of Mexico, and the southern Rocky Mountains, constitute its boundaries ; while, in higher latitudes, it ceases on the great plains of our western desert, long before we reach those Mountains. From what can be collected out of the travels and expeditions of Lewis and Clark, Pike, Long, Catlin, Fremont, and Gregg, not less than from fur traders and Santa Fe merchants, it is almost unknown at the distance of three hundred miles from the western boundary of the states of Missouri and Iowa, and above the latitude of 37° N. To the north it does not prevail as an epidemic beyond the forty-fourth parallel, and ceases to occur even sporadically about the forty-seventh.

The observations from which these limits are deduced have been made on the resident inhabitants included within them ; on travellers into portions of country as yet unsettled; and on the soldiery of the American and British posts. From these army returns I have, with all possible care, constructed two tables, which may properly be introduced at this place. The American returns* purport to be for ten years; but this is true of a few only; and many of the others vary from each other in the number of years through which they run, whereby the conclusions deducible from them, are entitled to less confidence than if an equal number of observations, in the same years, had been made at each post. As the number of troops was never the same at two different posts, nor during two years the same, one thousand has in the returns been assumed as the mean strength of the whole; and the number of attacks of Fever, and the actual mean strength, have both been brought to that standard. The results offered in the table, then, are not what any post did afford, but what any or all would have given, had the actual strength been at all times one thousand men. At several of them, it will be perceived the number of attacks exceed the number of men, implying that some individuals experienced several, in the course of the year. The returns are quarterly, but the quarters are those of the calendar year, and therefore, do not exactly correspond with the seasons.

The observing reader will perceive, that this table affords a variety of information : such as the decrease of the Fever in the north — its relative prevalence at different posts in the same latitude — the proportionate number of intermittent and remittent cases, and the comparative prevalence of both, in different seasons.

* Forry's Statistical Report of the Sickness and Mortality of the Army of the United States; prepared under the direction of Thomas Lawson, M. D., Surgeon-General, Washington, 1S40.

Showing the number of attacks of Autumnal Fever, in the different quarters OF THE YEAR, AT TWENTY-SIX MILITARY POSTS, BETWEEN THE GULF OF

Mexico and Lake Superior — the mean strength being 1000. Arranged according to their latitudes.

Twenty-six Posts.

Quarters of the Year.

Total of the Year.

Comp. of

annual

aggregates.

First. Second.

Third. , Fourth

Key West, N. Lat. 24° 33',

70 11

52 00

6 ! 51

! 00

179 11

Both,

Fort Brooke, N.

Lat. 27° 57',

80 13

190 24

308 28

760 89

Both, yy i 214

336 | 206

Fort King, N. Lat, 29° 12',

Both,

120 6

200 41

460 90

1194 193

126 041

550 | 470

Fort Jackson, N.

Lat. 29° 29',

8* ! 148 4 ; 9

816 128

367 46

Both,

«« | 157

New Orleans Barracks, N. Lat. 29° 57',

Both~

Both,

100 10

50 80

84 100

294 250

Fort Wood, N. Lat. 30° 5',

Fort Pike, N. Lat. 30° 10',

170 3

"192~~

1063 ! 1063

28 4

56 23

40 28

31 22

Both,

53 107 100

232 232

Baton Rouge, N.

Lat. 30° 36',

71 40

124 62

220 100

522 302

Both,

824 | 824

Fort Jesup, N.Lat. 31° 30',

46 12

123 33

44 12

239 63

Both,

Fort Mitchell, N.

Lat. 32° 19',

20 18

60 43

Both,

Fort Towson, N.

Lat. 33° 51',

242 16

107 37

450 114

269 30

1068 197

Both,

Fort Smith, N.Lat. 35° 22',

150 5

445 98

249 24

1034 127

Both,

INTERIOR VALLEY OP NORTH AMERICA.

Twenty-six Posts.

Quarters of the Year.

Total

of the

Year.

Comp. of

annual

iggregates.

First.

Second.

Third.

Fourth.

Fort Gibson, N.

Lat. 35° 57',

151 12

491 161

1193 242

Both,

Jefferson Barracks, N. Lat. 88° 28',

152 76

Tf9~

322 153

Both,

Fort Leavenworth, N. Lat. 39° 20',

100 1

151 3

205 16

143 10

599 30

Both,

101 9 6

Fort Armstrong, N. Lat. 41° 28',

70 30

72 73

30 17 47

181 126

Both,

7 3

Fort Dearborn, N.

Lat. 41° 51',

102 4

240 11

Both,

Fort Gratiot, N.

Lat. 43°,

46 1

286 10

333 16

110 1

775 28

Both,

Fort Crawford, N.

Lat. 43° 3',

260 41

Both,

Fort Niagara, N.

Lat. 43° 15',

117 20

52 62

57 20

248 120

Both,

Fort Winnebago, N. Lat. 43° 31',

3 4

5 10

18 3

49 14 63

Both,

Madison Barracks, N. Lat. 43° 50',

70 20

35 8

227 28

Both,

Fort Howard, N.

Lat. 44° 40',

2 2

28 22

10 3

51 38

Both,

Fort Snelling, N.

Lat. 44° 53',

9 3

28 11

11 3

45 17

Both,

Fort Mackinack, N. Lat. 45° 51',

7 1

37 4

16 4

16 4

76 13

Both,

Fort Brady, N.

Lat. 46° 39',

41 3

Both,

The British returns* are more limited, for the number of posts are smaller, and the range of country and climates less. They do not, moreover, give the relative number of cases in different seasons, or at the separate stations, and therefore express the prevalence of autumnal fever in Canada, generally, not in particular localities.

Exhibiting the Annual Prevalence of Autumnal Fever among the British

Troops in Canada.

Ratio of cases to the mean strength of 1,000.

Localities.

intermittent Fever.

Remittent Fever.

Annual

aggregate

of both.

Canada, between the latitude of 42° and 47°, from 1817 to 1836, inclusive— 20 years, - - -

Upper Canada, the principal Posts — Kingston, East end of Lake Ontario, N. Lat. 44° 8 / — Toronto, North side of same Lake, in 44° 33 7 — Fort George, mouth of Niagara River, in 43° 15' — Amherstberg (Maiden), West end of Lake Erie, in 42° 10 7 — from 1818 to 1827, inclusive, - -

Lower Canada, principal ports on the River Richelieu, which connects Lake Champlain with the St. Lawrence, latitude from 45° to 46° — Montreal, latitude 45° 31', and Quebec, latitude 4fi° 4-7/ _____________

This table, by embracing the Peninsula north of Lakes Erie and Ontario, together with the banks of the St. Lawrence, down to its estuary, completes what the other left unfinished ) and enables us to estimate the relative prevalence of autumnal fever, through every parallel of latitude, from the mouth of the Mississippi, to that of the St. Lawrence, and from Cape Florida to G-ros Cap, at the entrance of Lake Superior.

We should be aware, however, that the numbers in the tables do not always express, correctly, the cases of fever originating in the localities with which they stand in connexion. Thus, Maj. Tulloch, the compiler of the British Report, informs us that many of the cases of fever returned from the posts of Lower Canada, were relapses in patients from the posts of Upper Canada; and in the United States, our troops are often sent to more northern posts to recover from the fevers of the south j and thus by relapsing, add not a little to the number of cases at posts which otherwise might have presented but few.

* Tulloch's Statistical Reports on the Sickness, Mortality, and Invalidizing among the troops in the United Kingdom, Mediterranean, and British America: prepared from the Records of the Army, Medical Departments, and War-Office Returns, by command of Her Majesty, London, 1839.

Section III

CONDITIONS WHICH IMPOSE GEOGRAPHICAL LIMITS, AND GIVE UNEQUAL PREVALENCE TO AUTUMNAL EEVER.

I. Soil. — Under this term I include all that composes the surface of the earth, apart from its waters. The loose upper stratum of our Valley consists, as far as its mineral elements are concerned, of the debris of the rocks beneath, or of deposits of the debris of other rocks, spread over the surface by ancient inundations. There are tracts of country, however, in which the rocks themselves appear at the surface. None of these conditions favor the production of autumnal fever ; but on the contrary, it prevails least where they are most perfectly developed ; and hence there is no reason for referring the disease to emanations from a purely mineral surface.

The soil, however, may have another element than the mineral — dead organic matter, both animal and vegetable ; and this is its general character throughout the Valley. The amount of this element is very different in different places, for its production depends, first, on the fertility of the surface; second, on temperature; and third, on moisture. Where these conditions are all present, the growth of organic matter is redundant; where any one or more of them is wanting, it will be correspondingly limited. Thus it is small in quantity in the pine woods of the south (if we except the trees themselves), from the sandiness of the surface ; in the desert beyond the Mississippi, from the same cause, and also from the want of moisture; in the far north from the want of heat, yet it is abundant even beyond the limits to which the Fever extends ; on the Appalachian Mountains, from that deficiency in part, and from their rocky surface. Dead organic matter is, also, unequally distributed ; for the rains wash it down from the hills, and deposit it in the valleys ; where, adding to their fertility, it rapidly augments itself by promoting more luxuriant crops of vegetation.

Now, it is a safe generalization to affirm that, all other circumstances being equal, autumnal fever prevails most where the amount of organic matter is the greatest, and least where it is least. A diligent study of the topographical descriptions of Booh I. Vol. 1. will sustain this conclusion and demonstrate that decaying organic matter is one of the conditions necessary to the production of autumnal fever. As to the mode in which it co-operates, two opinions may be entertained : First, It may supply the material out of which a poisonous gas is formed ; and, Second, It may be a nidus or hot-bed of animalcules or vegetable germs. In either case, we may presume that all kinds of decomposing organic matter, are not equally favorable to the production of the cause of this fever; but, although I have sought for facts bearing on this question, a sufficient number has not been found to justify their presentation here. I hope the subject may attract the attention of others.

The first breaking up of the soil appears, from a variety of observation, scattered through our topographical descriptions, to be frequently followed by autumnal fever ; and on the other hand, long-continued cultivation is accompanied by diminution of that disease ; the element which contributes to its production becoming exhausted.

II. Living Vegetation. — Forests have been thought to modify the conditions which generate autumnal fever. Our medical topography supplies several facts, which go to show, that those who first penetrate our woods, and establish themselves in cabins, closely surrounded by trees, remain comparatively exempt from autumnal fever, till the clearing is extended. On the other hand, it is a disease of the country, and especially of newlysettled parts, where the amount of forest is so great, as to maintain a high degree of humidity. Our cities and larger towns, it is well known, seldom suffer, and they are to be considered, as in some degree, presenting the very opposite condition from our woodlands. Again, trees have been thought to arrest the spread of that gaseous agent, whatever it may be, which is said to be the true cause of the Fever; but in what manner they do it, no one can tell. It has been conjectured, that their leaves absorb the noxious exhalation; and also that they mechanically arrest the dissemination of the aerial poison. In harmony with the former hypothesis, is that of Dr. Cartwright (seeVol. I. p. 79), in reference to the Jussieua grand/flora, and some other aquatic plants, in the delta of the Mississippi ; which, he supposes, absorb the agent that produces autumnal fever. I have already expressed the opinion, that the facts do not establish that hypothesis ) and must here in conclusion, remark, that living vegetation is so mixed up with other conditions, necessary to the production of the Fever, that, in the existing stage of observation, its effects cannot be correctly estimated.

III. Surface Water. — In the maritime parts of Florida, Alabama, Mississippi, Louisiana, and Texas, surface water is abundant, for one side of each rests on the G-ulf, which has many inlets and little bays, the banks of which are inhabited. The rivers, moreover, are numerous, and as they approach the Gulf, expand into broad estuaries or deltas. The delta of the Mississippi abounds in lakes, lagoons, and bayous. As we ascend this, and the smaller rivers, wide cypress and liquidambar swamps, annually replenished, skirt both sides. The intervening plains are cut up by smaller streams, which have wide alluvions, often subjected to inundations ; and the country between them abounds in swamps ; from which even the sandy pine plateaus are not entirely free. This continues to be their condition, till we reach the flanks of the Cumberland Mountains, on the east, and those of the Ozark Hills to the west. As we ascend the Mississippi, to the mouth of the Missouri, we find its annual floods leaving small lakes, ponds, swamps, and lagoons ', which in the aggregate are of great extent, and but partially

INTERIOR YALLEY OF NORTH AMERICA. 25

drained or dried up, before the next inundation. Now, as we have seen, the whole of this region is infested with autumnal fever, beyond any other portion of the Valley.

In North Alabama, Tennessee, and Kentucky, swamps are almost unknown, except along the few rivers, which have wide bottom-lands, most of which, moreover, are exempt from inundation. The rivers, however, are sinuous, and in summer, sluggish and pondy ) and it is in their vicinity, chiefly, that autumnal fever prevails. In the states of Illinois, Indiana, and Ohio, the rivers generally flow through wide valleys, many of which are liable to be overflowed. Small lakes, ponds, and swamps, are also frequent, in certain portions of those states ; and it is precisely these localities, which are most infested. To the east of all the states mentioned, as we climb the mountains, the surface water is no longer found in basins ; and the streams, generally, have a rapid current, down narrow and rocky channels ; and here, autumnal fever nearly disappears ) or, when present, is confined to the valley of some stagnating stream. Everywhere, west of the states of Arkansas, Missouri, and Iowa, surface water is scarce ; the declivity of the plain which stretches from the Rocky Mountains, favoring its escape; while the subjacent sand almost absorbs even considerable rivers. Thus, as we advance into that desert, we come at the same time to the limits of surface water, and of autumnal fever. In the north there is no deficiency, for the whole country is essentially lacustrine ; and up to a certain latitude, the Fever prevails. Thus the shores of Lake Ontario and Lake Erie, with those of the southern extremity of Huron and Michigan, are infested, and sutler far more than the drier lands which surround them. But beyond these limits, on the shores of the two latter lakes, and on those of Lake Superior, the Fever, as we have seen, is never epidemic, although water is abundant ; and still further north, where small lakes, and their connecting streams, exist in countless numbers, the disease is unknown ; showing that, while water is essential to the production of this Fever, other causes must co-operate to give it power.

Let us inquire into the modus operandi of this agent in the production of the disease under consideration.

1. Under the influence of solar heat it impregnates the air with vapor, giving a high dew point; and other circumstances being equal, the evaporation is greatest where the heat is highest. This, of course, is in the southern part of the Valley, and there, as we have seen, the Fever prevails most.

2. Surface water not only contributes largely to the production of a luxuriant vegetation, destined annually to perish, but is indispensable to the decomposition of what it has aided in producing. Hence, without its agency, none of the deleterious gases, which are supposed to be thus generated, could have an existence. But its presence in any or all quantities, will not answer equally well. If there be too little, the molecular movements of fermentation are arrested for want of a solvent — if too much, the atmosphere, indispensable to the process, is excluded ; or the evolved gases are absorbed and retained.

3. Its presence is essential to those chemical actions, in certain soils, which are believed, by some writers, to generate exhalations that occasion the Fever.

4. It is equally indispensable to the production of both animalcules and microscopic plants.

5. Both evaporation and condensation are known to be accompanied by electrical perturbations.

Thus water is a necessary element, in all the hypotheses which have been framed to account for autumnal fever.

But a contrary and salubrious influence has been ascribed to water ; for it is held by many that this fluid absorbs the noxious gas or gases, which they believe to produce the Fever, and thus limits its prevalence. According to this opinion, the deep water in the centre of a basin, may imbibe and retain the noxious gases, which the shallow waters of its margins have contributed to generate; and, in support of the hypothesis, it has been affirmed that the vicinity of cataracts and rapids is more unhealthy than the banks of the rivers in which they occur. The absorbed gases are supposed to be there liberated by the agitation of the water. The medical topography of Book I. Vol. I. presents several facts bearing on this hypothesis. Thus Wetumpka, at the foot of the long rapids of the Coosa River; Louisville, at the falls of the Ohio River; and Maumee City, at the termination of the rapids of the Maumee River, are all infested with autumnal fever ; but other towns, on the same rivers, are likewise scourged with that disease ; and Oswego River, which drains the Montezuma swamps of Western New York, has at its mouth a great number of mills, yet the inhabitants suffer but little from that disease. It prevails still less at the Falls of Niagara ; and finally, at Zanesville, where a natural waterfall has been augmented by artificial means, and on the Kentucky River, where there are series of pools and dams, there is no special prevalence of the Fever. Thus the facts furnished by our Valley, do not prove that waterfalls eliminate a gas which is the cause of the disease under consideration.