Vaucquelin, Fontanelle), merely demonstrated the presence of decomposing organic matter in marsh-exhalations, and the theory has long been generally accepted that malarial poison is exclusively the result, in gaseous form, of the decomposition of vegetable organisms, such as carbonic acid gas, carbureted hydrogen, and according to Schwalbe, carbonic oxysulphide.

But although no analysis of the air has yet disclosed any immediate principle to which the unhealthy influence of malaria or marsh-miasm may be ascribed, still, if we admit its existence as the efficient cause of the disease in question, it is easy to see why the rates of mortality by these fevers in California, thus determined by positive statistics, are just in the proportion in which they are found in certain parts of the State. A rich alluvial soil, abundant vegetation, rivers and creeks whose banks are subject to overflow, and inundations of vast prairie lands, which every year occur to a greater or less extent-these conditions, conjoined with a high Summer temperature, together with sudden and sharp transitions from the heat of mid-day to chilling nights, are the well recognized hypothetical factors concerned in the production of malaria; and it is precisely in those regions where the greatest mortality and sickness, caused by malarial diseases, as just seen, happens, that the concurrence of all the conditions, just enumerated, is met with in the fullest degree. Of all the elements which enter into the sum of these conditions, water seems to play the most active part.

Geographical facts, collected by medical writers from Hippocrates downwards, show that every country is unhealthy in proportion to the quantity of undrained alluvial soil it contains; the inhabitants of such districts dying often in the ratio of one in twenty, instead of one in thirty-eight-the average mortality in healthy countries. Ancient Rome was once the seat of so many fatal epidemics that the Romans erected a temple to the goddess Febris. Those epidemics were known to arise from the great masses of water, poured down from the Palatine, Aventine, and Tarpein hills, becoming stagnant in the plains below, and converting them into swamps and marshes. The elder Tarquin ordered. them to be drained, and led their waters by means of sewers to the Tiber. These subterranean conduits ramified in every direction under the city, and this system of drainage, which was continued as late as the Cæsars, rendered Rome proportionably healthy, and the seat of a larger population than has since, perhaps, been collected within the walls of any city. On the invasion of the Goths and Vandals, however, the public buildings were destroyed, the embankments of the Tiber broken down, the aqueducts laid in ruins, the sewers obstructed and filled up, and, the whole country being now again overflowed, Rome once more became the seat of an almost annual paludal fever, as in the times of her earliest foundation.

Referring to the numerous facts of a similar nature bearing upon the etiology of fevers, and which are to be found in the works of Lancisi, Baglivi, Rigault de L'Isle, Maccullock, Furguson, Rush, and a host of writers, I would here remark that it appears, from an extensive investigation of the subject, several years ago, by the English General Board of Health, the conclusion was arrived at that wherever water is laid on the land in greater quantities than it can immediately or very soon absorb, or wherever there is alternate wetting and drying, the effects of malaria, if other conditions be favorable, are sure to be manifested. Instances upon instances have been brought forward, not only from England, but from other countries where irrigation is practiced, of the

appearance and disappearance of fevers coincident with the operations of flooding and drying particular tracts of land. In the LombardoVenetian provinces, where there is some of the oldest, most extensive, and skillfully conducted irrigation in Europe, the Government long ago found it necessary to interfere for the protection of the health of towns. By law, as stated on positive information received by the same high source, just referred to, from the authorities at Milan, "permanent" irrigations are prohibited within five miles distance of towns. This range, that has been assigned by experience and predicated upon the most carefully observed facts, to the influence of malaria so far beyond its source or origin, taken in connection with the numerous instances, resting upon the most respectable authorities, of the febrile cause being borne in the common atmosphere, as, for instance, from Holland to England-of ships receiving the infection at a great distance from landtogether with the collateral evidence afforded in Europe, from the frontiers of Asia to the other extremity of that continent, and particularly in Italy, that as the western coast presents a larger surface of infections, so malarial fevers prevail more extensively under the influ ence of southwest winds than of the opposite currents. All these corroborating circumstances not only tend to render it highly probable that the noxious agent must be a product of vegetable decomposition changed from a fixed to an æriform state, and evolved in the lower regions of the atmosphere, and to place the question of the morbific effect, at a distance, of winds passing over pestiferous localities almost beyond the possibility of a doubt, but also satisfactorily account for the wide diffusion of malarial fevers throughout the length and breadth of this State (1) disseminated from the generating foci, the watercourses, sloughs, reservoirs, etc., in all directions, just as they happen to be located.

Indeed, if facts were wanting to establish the point in all the hypotheses which have been framed, concerning the etiology of these fevers, that moisture, at a given temperature, is one of the essential elements in the production of its remote causes, and that these causes can be wafted to great distances from their sources, the medical history of our State abundantly supplies.

MEDICAL HISTORY, ETC.

In reproducing, therefore, in part, for the benefit of the public, for whom the publications of the State Board of Health are prepared, what was advanced by me in eighteen hundred and sixty-five, in my report to the American Medical Association, I will hear repeat that, prior to the Fall of eighteen hundred and fifty-eight, when autumnal fever prevailed so extensively, the plains, as well as the mountains of California, were proverbial for their salubrity. With the exception of the irregular development of confused forms of fever in towns and isolated localities, chiefly where stagnant water existed, and of intermittents in the neighborhood of exposed river-courses and low places, which are inundated

(1) Lancisi was among the early writers, already referred to, who recognized the agency of the wind in aiding the spread of malarial fevers by virtue of its power of carrying material disease-germs. He attributes to the influence of the winds the fact that the Roman Campagna became more unwholesome after the removal of the sacred groves, and its consequent greater exposure to the miasm of the Pontine marshes. Similar testimony may be found in all ages, and of the most varied kind.

during certain portions of the year, endemic diseases were comparatively unknown-at least after the introduction of the comforts and ameliorations of civilized life, and when men ceased to overtask and expose themselves in the reckless manner peculiar to the earlier immigrants. But how stands the case now? An extensive system of irrigation has been inaugurated in the Tulare, San Joaquin, and Sacramento Valleys for agricultural purposes, which, unless the contemplated drainage be carried out in the most thorough manner, in accordance with the precautionary suggestions of the Board of Government Commissioners, will render our wheat fields no mean rivals, in unhealthfulness, of the notoriously miasmatic rice fields of our Southern States.

For mining purposes, canals, thousands of miles in aggregate length, bave already been dug in all directions, without a thought as to alignment or drainage, to lead the water in innumerable serpentine courses from the rivers into the placers, towns, and settlements, and nearly every valley that can be dammed on the line of these ditches has been appropriated as reservoirs to hold water. The action of an almost tropical sun upon the decaying vegetable matter that remains in these canals and reservoirs, especially around their margins, has been manifested in its effects. Not only in the plains and agricultural regions, but along the whole range of the foothills, from Shasta to Merced, as indicated in the accompanying map, malarial fevers prevail more or less every Fall. In eighteen hundred and fifty-eight, so universal was the endemic that it might have been properly termed an epidemic. At Folsom and in the neighboring country, previously regarded as particularly free from miasmatic diseases, scarcely a miner escaped. In Placer the effects were most alarming, not in fatality, but in extent. The following paragraph from the Placer Press, published in Auburn, gives a concise explanation of the circumstance:

"Almost everybody living west from Gold Hill is either down with fever, or chills and fever, or more or less affected by the miasmatic poison generated and floating around in that locality. The cause of this unusual sickness is generally chargeable to the reservoirs of the several ditches. They are filled with sedimentary water, which spreads over a large plain during the day, exposing a great surface of wet vegetable matter to the sun, as the water is drawn down. This is a most unfortunate fact, as without reservoirs the county cannot be mined, and sickness destroys the ability to labor. What can be done to remedy the evil?"

To show further that I am not drawing upon imagination to make out a case of deep and pervading interest, but stating actual facts, patent and accessible to every one, I will here cite a few other statements from the newspapers of that period, as affording the best historical record of past events:

The Citizen, published at Monte Christo, after noticing the extraordinary fact, clearly indicating a pestilential constitution of the atmosphere, of an almost universal tendency of every bruise, cut, applications for neuralgia and rheumatism, such as blisters, etc., to result in the formation of abscesses, alludes, likewise, to the "general prevalence of sickness."

The Butte Record, of Oroville, at the same time, stated: "The work on the deep shaft has been suspended, in consequence of illness among the company that has it in charge. A great deal of sickness exists among the bluff miners, more than any previous year." About the

same period the following card, addressed by the citizens of Oroville to the editor, appeared:

"The undersigned, citizens of the Town of Oroville, having wit nessed with deep regret, during the past month, the sickness which (heretofore unknown to us) is this Fall afflicting nine tenths of our people, injuring business, and which now threatens to impede the future. growth and prosperity of our town, (1) would respectfully suggest that, as it is now a conceded fact that our sickness is the result of inhaling the miasma arising from the stagnant waters to the south and west of the city, a meeting be called at the Court House, on Tuesday evening, October nineteenth, at seven o'clock P. M., for the purpose of taking steps to remove the nuisance:"

The same paper has the following remarks:

* *

"The successful working of the river claims demands a longer season of dry weather; the health of the country seems to require rain. Health is of vastly more consequence than the accumulation of gold, and we pray for rain even at the expense of the river miners. Accounts from other sections of the State show that this region is not the only one infected. Similar complaints to those experienced here prevail along the Yuba and in many of the mining and agricultural districts of the foothills."

Unfortunately for the future welfare and prosperity of this town, the unusual occurrence of the most copious rains ever experienced in October, followed by heavy frosts, obviated for the time being the necessity of the active steps called for, and nothing has since been attempted, either in that locality or elsewhere, to prevent a repetition of the same calamities. The conditions favorable to the evolvement of the febrile poison, although interrupted at that time by the change of season, remain not only the same but are renewed every year, over a wider field, with more or less potency (2) In fact, in no other country or epoch in the world's history than in California at the present time has man's action ever been known to change so rapidly or so permanently the face of nature. Millions of tons of soil are washed down annually through the Sacramento and American Rivers and their tributaries. Each ton of soil so transposed by the hydraulic ram not only incapacitates a certain area of high land for the growth of timber and other vegetation but also tends to raise the river bottoms. And although the terrible effects of outraged nature which the history of analagous civilizations and circumstances teaches have not yet manifested themselves strongly enough to arrest general attention, still it is only a question of time when, by the denudation of our mountain slopes of their forest growth, a more rapid melting of their snow must follow, and consequently increased frequency and violence of freshets and coincident floodings of the low lands. Unless, therefore, some effort is made towards correcting and providing against the evils resulting, in a sanitary point of view, from the present and prospective modes of spreading water over the surface, the most valuable portion of California will become more and more obnoxious to the health of the inhabitants during the autumnal months. It is due, therefore, to the State, with whose general prosperity and welfare our own interests are identified, and

(1) The soundness of these predictions have been confirmed by time.

(2) See the account of the late epidemic, in this report, among the Chinese on the Feather River, near Oroville.

especially is it due to the science we cultivate, that the sanitary bearings of this subject should be investigated in a philosophical manner, especially by the State Board of Health and the members of this society, most of whom have been living in the midst of the malarial region for nearly a quarter of a century. We can all speak of these diseases from direct practical experience; and taking it for granted that every one admits of the existence of its cause in the atmosphere, I trust that, by thus directing attention to the conditions already stated to be connected with its evolvement, to elicit your opinions, either to confirm or invalidate whatever I may further advance. In this manner I may be enabled to diffuse, through the reports of the State Board of Health, some sound practical knowledge on a subject of deep import, as well to the science of medicine as to that of political economy.

The question which naturally suggests itself here is: If water has the agency attributed to it in the production of the toxical effects under consideration, what are the concurrent circumstances necessary to give it potency or efficiency?

MEDICAL TOPOGRAPHY AND HYDROGRAPHY

supply many facts which go to show that though malarial fever prevails perpetually and virulently within the tropics, there are still places having the same temperature, but varying in other conditions, that are never affected by it. The Summer heat of our southern desert is intense, but those who traverse it and keep at a distance from its watercourses remain perfectly healthy. ·

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 absorbs. even considerable rivers. Thus, as we advance into the desert, we come at the same time to the limits of surface water and malarial fever. That the heat here is sufficient to engender malaria, if that was the only necessary condition, is proved from the fact, that far to the north of this region, where the whole country is essentially lacustrine, the fever prevails. Thus the shores of Lake Ontario and Erie, with those of the southern extremity of Huron and Michigan, are infested, and suffer far more than the drier lands which surround them. Beyond those limits, on the shores of the two latter lakes, and on those of Lake Superior, the fever is never epidemic, although water is abundant. Still further north, where small lakes and their connecting streams exist in countless numbers, the disease is unknown, while under precisely the same conditions in Florida, Alabama, Mississippi, Louisiana, Texas, Illinois, Tennessee, Kentucky, Indiana, Ohio, and other States, it never fails to show itself in Autumn. These facts show that water and a certain degree of heat are essential to the production of the disease. From the diligent study of these hypothetical causes, and their comparison with other instructive facts furnished by our army statistics, the late Dr. Daniel Drake inferred that a mean annual temperature of sixty degrees is necessary for the production of the fever, and that it will not prevail, as an epidemic, where the temperature of the season falls below sixtyfive degrees. The following is an abstract of some of the conclusions, as to the modus operandi of these agents, arrived at by the same high authority just quoted:

"Surface water not only contributes largely to the production of a luxurious vegetation destined annually to perish, but is indispensable to