Setting aside the great advance that has accrued to our knowledge since the discovery of the connection between mosquitos and malaria , yet even prior to this there were few infectious diseases so thoroughly under control in regard to their avoidance as malaria. It was the cultural activity of the race that converted severely infected, death dealing malarial foci into salubrious, thickly inhabited territories, and it was the devastations of barbaric hordes that changed these fertile fields to their original condition.

The general prophylaxis of malaria could, up to the discovery of the mosquito malarial cycle, be stated in the one word, " cultivation," and this, in a sense, is still true. It will be well, then, to recall here some of the older examples, based as they were on practical experience, and then to discuss how the matter now stands in the light of our present knowledge. The basis of malarial prophylaxis consisted in the rendering of the soil unsuitable for the development of the parasite, as it was then thought, but as we now know, the unsuitabilfty refers to the development of the mosquito.

This problem may be easy or difficult, even impossible, according to the circumstances surrounding individual cases.

It was a very different matter, for instance, to change the condition of a limited malarial focus in the midst of a thickly populated rich country, and do the same for an extensive, thinly populated, impoverished malarial district. A highly situated, easily drained swamp offered scarcely any difficulties, while a district covered here and there with brackish water, and lying on or under the level of the sea, might have presented insurmountable ones.

It is not our intention to discuss in extenso these different methods for improving the " sanitary" condition of the soil. This is the work of the hygienist and the sanitary specialist. For detailed information we can recommend the monumental work of Fichera. Still, we may say that all these old and well tried methods had this common aim, the regulation of the ground moisture so as to promote fertility.

The following measures seemed to the earlier school of hygienists particularly important: The walling off of the sea or rivers in order to avoid flooding, the separation of fresh from salt water in order to prevent the formation of brackish water, canalization, drainage, the filling up (colmata) of deep lying basins, and the refilling of ditches opened up in ground working (especially the building of railroads).

Exceptionally during severe epidemics radical measures were undertaken, as, for instance, the copious flooding of malarial foci. This was first put into practice by Empedocles, later by Lancisi.

These regulations were to be accompanied by cultivation, without which the end was rarely attained. It was, as it seemed, necessary to bend the malarial soil to the yoke, and exhaust its strength in a useful way, in order that it might not be employed in the production of miasmata. The ground could not be left as a pasture, but had to be systematically planted with grain, sugar cane, eucalyptus, etc. The special properties of the soil and the climatic conditions of the locality decided the choice of plant. These hygienic regulations occasionally produced extraordinary results.

It was evident that the turning up of the earth necessarily associated with sanitation caused a considerable sacrifice of capital and human lives. Every movement of the soil in malarial region appeared to carry with it the greatest clanger for the laborers. Enormous loss of life had, for instance, resulted from the building of railroads through malarial foci.

In the summer of 1805 the La Chartereuse swamp near Bordeaux was drained. The result was 12,000 cases of pernicious fever, with 3000 deaths. According to L. Colin, there were 109 deaths from pernicious fever in the year 1881 in the Arronclissement Bastia among the railroad laborers and wine growers.

Sanitary measures have been carried out in all the civilized countries of the world. We may recall the number of endemic malarial foci in Germany, Austria-Hungary, England, France, and Holland, even at the middle of this century. The steady development of hygiene, the increase of the population, and the improved condition of the people, as well as the advance of industry, have bestowed immunity on districts and territories infected for centuries. A glance into the publications of older writers demonstrates the difference between then and now. Formerly the cases were innumerable; now they occupy but a very small space in medical literature. Berlin, Vienna, Prague, and other large cities all showed then pernicious malaria , while now they show only a few mild cases of intermittent.

Drainage and canalization accomplished magnificent results in

Ireland, England, Austria, Holland, and North America. In Austria, Pola was an instructive example. At the present time it is a growing town, the principal harbor of the Austro-Hungarian marine, and shows a very small morbidity from malaria , while a few decennia ago it was notorious and dreaded. The drainage and canalization of the Prato grande and Piccolo, the conversion of this desolate waste into a maneuvering ground, and similar regulations, carried out on Jilek's proposal, were the agents by which the rapid results were produced. This is evident from the fact that an inadvertent obstruction of the drainage canal was sufficient to allow a renewed outbreak of the endemic, though this was soon interrupted.

The building of dams has also contributed more or less in all civilized countries to the combating of malaria , though to the greatest extent in the Netherlands. Swamps were laid dry, especially in Holland and Italy. The delta of the Tiber and the Ostian swamp have been, after considerable effort, regulated and in part drained, with the result that a diminution in the cases of malaria has been obtained.