Page images

means of restoring to animals and to man a sufficient and normal amount of Oxygen, to replace that which may have become consumed by animal respiration, and the various operations of nature and of art. The physician, in his investigations on the cause of disease, and as guardian of the public health, more es pecially in reference to diseases of an epidemic character, has not been silent in ascribing to it a salutary or deleterious agency in proportion to its presence or absence, and as exerting an important influence on the health of individuals and of nations, varying with the time, the season, and the temperature.

A substance, the knowledge of which seems to be fraught with life and health, both to the animal and vegetable kingdom, and which must, as a consequence, have an important bearing on the agricultural and commercial wealth of nations, demands from the man of science, a calm and patient investigation, so as to give to it a proper place in the annals of true science.

It is for this purpose that the present observations are submitted, trusting that in so vast a field for enquiry, many may be found as co-labourers—willing to contribute, however little, to the vast treasury of true knowledge.

As far back as the end of the 18th century Van Marum, in experimenting on the electrical action on oxygen speaks of the odour or smell being very strong, and which appeared to him as the smell of electrical matter, and it is scarcely to be doubted that Gilbert, Hawksbee, Dufay, Franklin and others were equally sensible of the peculiar odour generated by electrical action.

It is about 19 years ago since Schonbein, during his investigations on the decomposition of water by the Voltaic pile, remarked the odour that became manifest, and in a letter written to Arago in 1840, be says, “that for some years past he had been familiar “ with the odour generated during the decomposition of water by " this voltaic current,” and to this simple elementary body he gave the name of Ozone (from ozo, to smell).

The first accounts of the investigations of this substance may be found in the" Memoirs de la Société d'Histoire naturelle de Bale," in the “Journal de chimie pratique,” Erdmann in the “ Annales de Poggendorf,” also in the “ Archives de l'Electricité” de Marignac et De La Rive, and also in the various British scientific periodicals.

Schonbein at this period of his investigations believed it to be a simple elementary body analogous to chlorine, bromine and

iodine, but his opinion soon became modified, and he declared that nitrogen was not a single body, but consisted of hydrogen and Ozone, and it was supposed really to be a component of nitrogen; and his opinion was supported by Assam, who showed the identity of atmospheric Ozone, and Ozone produced by chemical action or decomposition: further investigation led to the opinion that it was a peroxyde of hydrogen.

Schonbein soon abandoned the opinion that Ozone was a component of nitrogen, and inclined to the opinion that it was a peroxyde of Hydrogen. Marignac and De la Rive demonstrated that Ozone could be formed without the presence of nitrogen. And Berzelius had already expressed an opinion that it was oxygen in a peculiar state.

At this period of its history, Fremy and Becquerel urdertook a series of experiments illustrating the action of electricals upon oxygen, and proposed the name of l'oxygene Electrise which seems to have been at that time also adopted by Schonbein. Its presence in the atmosphere and its special production, has placed it beyond doubt as a substance possessing peculiar chemical properties, although several methods have been adopted to produce it artificially, such as the action of sulphuric acid on bichromate of potash, and also on the peroxide of lead, the most simple and easy method is by the use of Phosphorus. The process generally adopted is by taking a stick of phosphorus, cleanly scraped, about half an inch long, and putting it into a large bottle which contains just sufficient water to half cover the phosphorus, and then slightly closing the mouth, and letting it stand for some time at a temperature not less than 60°F. Ozone soon begins to be formed as is shown by the rising of the whitish fumes from the phosphorus which at the same time begins itself to be luminous. In a few hours the quantity will be considerable, and the bottle is then to be emptied of its contents, washed out and closed for use or experiment. The necessary conditions are that the air should be at the ordinary atmospheric pressure and at the temperature of about 60° F; humid and cold air retards and will scarcely give rise to its formation, and if the atmosphere be subject to an increased pressure, Ozone is not formed except by an increase of temperature : the presence of certain gases also prevents its formation.

It is also obtained by the decomposition of water by galvanism, and it may be formed in pure and dry oxygen gas by passing through it the electric spark. It may be said also to be formed generally when chemical combination takes place in contact

with the atmosphere, and the consequent reaction or disengagement of oxygen.

It is probable that oxygen may be modified more readily by electric action than any other gas, and it has been shown by bequerel, Faraday and others, that it may be rendered magnetic.

Ozone is colourless, possessing a peculiar odor, resembling chlorine, and when diluted, cannot be distinguished from the electrical smell. Its density, according to Andrew & Tate, is said to be four times that of oxygen. It is a most powerful oxydizing agent, converting most of the metals into peroxides, it is very slightly absorbed by water after long contact,—a very high temperature destroys its properties,—it possesses bleaching properties, hence its affinity to chlorine; it combines with chlorine, bromine, and iodine. It is rapidly absorbed by albumen, fibrine, blood, &c. It is a most powerful disinfectant, and when largely diffused in atmospheric air causes difficult respiration, acting powerfully on the mucous membrane, and in still larger quantities may become fatal.

During the past year, Schonbein has been actively engaged on the modifications of oxygen, and is of opinion that there are two kinds of (allotropic) modifications of active oxygen, standing to each other in the relation of positive and negative, and that there are a positive active and negative active oxygen-an ozone and an ant-ozone which in being brought together neutralize each other.

Clausius has endeavoured to account for the relation of volume existing between simple and compound gases, by the assumption that in simple gases several atoms are combined to form one molecule of oxygen, that for instance one molecule of oxygen consists of two atoms of oxygen, and is of opinion that under special circumstances it may happen that among the number of molecules in a given quantity of oxygen some may be decomposed into separate atoms. These would differ in their relations towards other substances, from those combined into molecules, and he considers these uncombined atoms are Ozone. .

Fortunately its presence, both in the state produced artificially in the laboratory, and also in the atmosphere, is easily detected. Its rapid production, its peculiar smell and other properties, render it somewhat less difficult to investigate than many other substances. We purpose more especially to consider its nature and influence in reference to Meteorology and its influence on animals and plants.

(To be continued.)

ARTICLE XIII.— On the Relative Value of Human Life in Diffe'rent Parts of Canada. By Pallip P. CARPENTER, B.A.

(For the Canadian Naturalist.) While the naturalists and geologists of the Royal Mount throw light on each other's studies in reference to extinct Palliobranchiates or recent Gasteropods, it may not be out of the province of this Journal to record facts in reference to living men and women; and those who would have been living bad not the teachings of modern science been disregarded, or considered as of secondary importance to the pursuit of money or of power.

The exact connection between those sanitary conditions over which man bas control, and the actual number of deaths in any town or district, is no longer a matter of hypothesis. The very accurate system of registration of births and deaths which has been carried out in England for more than 20 years, and of which classified returns are regularly published by the Registrar-general, bas enabled chemists, physiologists, statisticians and other sanitary reformers to compare their theories with recorded facts, and to check off their reasonings, by the average of a long series of years. The following instance will shew the precision with which sanitary reformers can now predicate the rate of mortality according to the external circumstances of drainage, ventilation, &c. While Mr. P. H. Holland was registrar of the southern portion of Manchester (called Chorlton-upon-Medlock) he went ibrough each district, tabulating each street,court, &c, in three columns, judging by his senses and knowledge what their rate of mortulity was likely to be. In each street he also made a threefold division of the houses, according to their character. Here therefore were nine divisions, to each of which he assigned a supposed proportion of deaths to population. He then directed his clerk to tabulate the actual deaths in each of these divisions, taking the average of five years. On comparing the theory and the facts together, in no case did they vary more than one-half per cent. The following are the results, omitting the fractions : Deaths per 1,000 inhabitants in houses | houses. houses.

In Best | Tiddling Worst i

[merged small][ocr errors][merged small][merged small][ocr errors][merged small]

Thus the inhabitants of the best houses, in the best streets, live more than twice as long as those in the worst houses of the worst streets.

The existing state of knowledge in England on these subjects. may be gained (1) from the quarterly and annual reports of the Registrar-general ; (2) from the reports of Her Majesty's Commissioners on the Sanitary Condition of the working classes, and on the Health of Towns; (3) from local reports and tracts published by the various Health-of-Towns' Associations. The present laws of England will be found in the “Public Health Act,” and especially in the “ towns-improvement clauses." All these documents could be obtained, either gratuitously or at a very moderate expense, on application to “P. H. Holland, Esq., H. M. Commissioner for Burial Grounds, Burial Board, Whitehall, London, England." They would form a very important addition to the public libraries of every Canadian city.

It is not to be expected that in a newly settled country, where the population greatly fluctuates, according to the accidents of immigration or commercial prosperity, the same accuracy of detail can be arrived at. But, by collecting the facts already accessible, we can both take measures to guard against errors in future returns, and shew the necessity of immediate sanitary regulations.

For the year 1851, we are in possession of tables, very carefully drawn out, both of the population and of deaths, arranged according to different ages and conditions, in the various cities and districts of Upper and Lower Canada. By comparing these, one with another, and taking the average number of deaths for every thousand inhabitants during the year, we obtain the following cesults; the fractions here, as elsewhere, being disregarded.

For the purposes of comparison, statistics are added from England, where the returns are most accurately made, and the causes of error most carefully guarded against; and from the last official Re. gistration Report of Massachusetts, as being a long settled State, in climatal conditions not very dissimilar to those of Canada. The general mortality of the principal part of Rhode Island is also added, from the Government Report.

« EelmineJätka »