Ozone-its effects on malarious fever.

IV. VIOLENCE AND ACCIDENTS.-Vulnus incisum, 30; contusio, 24; fractura, 12; snake bites, 13.

The unhealthy season commences later in the Gambia region than on any other part of the coast, as the commencement of the rains is later. The sickly weather begins about the end of June and during July. At Sierra Leone and Liberia the rains commence early in May, and the sickness then begins to manifest itself; and it is a known fact, that the report of epidemic is generally heard of one or two months at Sierra Leone ere it is heard of in the Gambia. On the Gold Coast station the commencement of the rains is not so unhealthy, from the exposed state of the different stations to the constant sea breeze and the perfect ventilation which is the result. Lagos and other parts in the Bights, not being so much exposed as the Gold Coast, are very unhealthy.

One of the causes of the unhealthiness of the beginning of the rains is the diminution of atmospheric ozone. The effect of this important agent in malarious fever has occupied my particular attention. Being stationed for some time in the hotbeds of malaria, I had ample opportunities of observing the various changes which take place in the system when under the operation of both.

The quantity of ozone in the atmosphere has an indisputable effect on the influence of fever in malarious districts; when it exists in large quantities cases of fever are generally few, and when in small quantities, fever is more frequent and of longer duration.

When the quantity of ozone in the atmosphere is very large, one may with impunity expose himself, in places where malaria is rife, without the manifestation of its constitutional effect for days or even weeks; and although a large quantity of ozone in the air destroys evidently a large quantity of the substance we know as the harbinger of fever, itself, at the same time, undergoing decomposition and destruction, yet still that which remains may be inhaled in sufficient quantity to lead to a paroxysm, although prevented from manifesting

itself by the powerful influence of ozone, which is taken into the system by respiration and impression on the exposed sentient surface.

It would appear that the quantity of ozone taken into the lungs, or the quantity taken into the system, in an undecomposed state, is insufficient to neutralise, or destroy in toto, the quantity of malaria accumulated in the system. When the latter is in large quantity, it can only prevent it from manifesting its paroxysmal phenomena. Two cases which I carefully watched will be sufficient to illustrate the opinion above stated. An officer who lived with me in the same fort was very fond of sporting. During the latter end of April 1860 he was accustomed to go out shooting every morning in the marshy swamp along the banks of the lagoon, in the Bight of Benin, but he was never ill. The quantity of ozone in the atmosphere was very large, ranging, at an average-the maximum during day, 8°; minimum, 1°; during the night, maximum, 9°2; minimum, 2°. When the quantity diminished, which it did in the middle of May, none being detected on some days, the maximum average in the day was 1°; minimum, 0°·2 ; in the night, maximum, 5°5; minimum, 0°-4. Without at all exposing himself, he had a severe attack of remittent fever, which was only cured after a large quantity of quinine had been administered; and without a subsequent exposure, he had a fit regularly every two weeks as severe as the first, and to put a stop to its mischievous effects on the system, I ordered quinine to be taken a day before the end of the two weeks, or the expected day of the attack, which had the desired effect of preventing its recurrence.

The other case is my own, occurring during the latter part of June of the same year. I was accustomed every evening to go out shooting on the marshy banks of the lagoon, and was perfectly free from any attack of fever, although from the small quantity of rain which fell, and the unusual burning heat of the sun, I was perfectly certain that a large quantity of malaria was being generated from these sources. The quantity of

ozone in the atmosphere was then very large, being, during the day, maximum, 10°; minimum, 1°; and during the night, maximum, 8°; minimum, 3°. I desisted from the expedition from having no small shot, and used then to take my walks on the shores of the Atlantic, and consequently beyond the reach of malaria. But a week after, when the ozonometer fell, the feverish symptoms began, producing entire loss of sleep, with severe headache, and continued for three days, but were subdued on the fourth day. The quantity of quinine taken was comparatively small, being only six grains. A week after I had another attack, but three hours later than the first. I now, however, took the precaution of taking quinine on the morning of the next Saturday, and similarly for some time, until I was perfectly free from fever. Other like cases might be cited, all tending to prove more or less the point in question. Sometimes the quantity of malaria taken into the system is so great that the small quantity of ozone absorbed is not sufficient to keep it in check, and in such a case the effect quickly manifests itself.

When there is a large quantity of ozone in the atmosphere, a small quantity of quinine alone is sufficiently requisite to check malarious fevers. Six grains are sufficient in an ordinary case; but when the quantity of ozone is small, more than double that quantity will be insufficient, and, indeed, in many such cases I have been obliged to give from fifteen to twenty-four grains before I could check its progress.

The conclusions to be deduced from the foregoing are:

1. That the larger the amount of ozone in the atmosphere, the smaller will be the number of malarious fevers prevalent or manifesting themselves; on the contrary, the smaller the quantity of ozone the greater and more fatal will be the number of cases of fever amongst the population, cæteris paribus.

2. The quantity of ozone in the atmosphere, even when large, does not neutralise the whole of the malaria generated from the different beds scattered on the earth's surface, but a certain quantity is always left, which is absorbed and accumu

lated in the system until a quantity is received sufficient to overbalance the vital changes in the different essential organs, or the proper motion of the sympathetic action, leading to the development of the fever.

3. That in cases where there is a large quantity of ozone in the atmosphere, the quantity received and absorbed through the lungs and the general surface into the system undecomposed, aided by the chemico-vital changes, is able to check the manifestation of its influence, but not entirely to annihilate it.

4. That when the quantity of atmospheric ozone is small, and consequently a small quantity, or none at all, is absorbed into the system, the chemico-vital changes being no longer able alone to prevent the manifestation of the poison, the fever bursts forth in full vigour.

Chemistry has not as yet supplied us with the means of collecting and preserving ozone to any length of time. Being a powerful oxidising agent, its formation is easily followed by its decomposition or deoxidation; and when the chemist will tell the physician that he has found a method by which he can not only form a large quantity of ozone, but preserve it for a considerable time undecomposed, the physician will say that he has at his command a powerful means for checking the progress of malarious fever far superior to that of quinine.

From noticing the effects of small quantities of ozone in the air on patients suffering from fever in malarious districts, I am led to conclude, that should the chemical experiments succeed, we shall be able to cure endemic fever as soon as the symptoms begin to manifest themselves, and the system will be freed from the tedious and exhausting process of cold and sweating stages.

Although the quantity of ozone in the atmosphere may be small when compared with the constituents of the air, being, under ordinary circumstances, according to M. Bérigny of Versailles, only one part in ten thousand, yet it must be admitted, that when in any quantity, some portion cannot but be absorbed in the mucous and general surfaces, and be able to affect the system. This is clearly proved, when we consider that a

Sanitary report of Quittah.

healthy man in twenty-four hours absorbs no less than 576.000 cubic inches of air; that he breathes twenty times in a minute, and at such times takes into his lungs twenty cubic inches of air. This volume of air, impregnated with any substance, hygienic (ozone) or mephitic (malarious), comes in contact at each respiration with no less than 201·600 square inches of absorbing surface in the air-passages and bronchial cells. If, then, the ozone in the atmosphere is pretty well developed, a quantity could be absorbed sufficient to check or put a stop to a moderate quantity of malaria.

Along the Bights, on the Guinea Coast of Africa, the lagoon is the source of the most deadly emanations; and I may here quote, verbatim et literatim, a sanitary report of Quittah station (Bight of Benin) for the two weeks ending the 31st May 1860, which I forwarded to the principal medical officer of the Gold Coast command:

"In viewing the sanitarium for the last two weeks of May, I have to report very unfavourably with respect to the amount of disease, when compared with the corresponding weeks in the preceding months. It substantiates the now universally believed fact, that the beginning of the rains is the most unhealthy time in the year, fever being more virulent than at any other period, even more than at the harvest or end of the rains.

"The sanitarium of Quittah station may be examined internally, that is, within the fort, and externally, in the town and neighbouring villages. In the fort much mischief does not exist amongst the men. Besides two cases of fever, there were one of Guinea-worm and one of orcheitis, viz., one in 5.3 ill.

In the towns and neighbouring villages there had been several cases of fever, some very severe, others mild, both amongst native and foreign inhabitants, either of long or short residence.

"It would appear that vessels in the roads are not exempt from it. Not that the infection travels over the sea, haud quaquam, but they obtain the infection by landing, as soon becomes manifest. Facts corroborate this statement, for the