Page images

presence of coal-beds', affords another probability. Fire-damp, or carburetted hydrogen gas, appears to be generated by the decomposition of iron pyrites in coal, and may often be heard issuing from the fissures in coal-beds with a bubbling noise, as it forces the water out along with it; but it is also a product of the decay of any organic matter when air is present in deficient quantity, or more properly speaking of putrefaction with limited access of air. Iron pyrites are very common in the clays and other rocks of the Scotland district.

The bituminous coal has been hitherto used as fuel in the taich-furnaces of several estates, where it has been combined with megass, and likewise with bituminous clay to prevent its rapid melting and running into a tar, by which a great portion of it is lost, as it runs through the bars of the furnace-grate without igniting. In Wales the labouring class resort to a compound of the small coal which is quite unmanageable for firing, and mixing it with turf and clay into balls, it is dried and used as firing, and is said to give a steady glowing heat without much flame. Asphalt has been extensively used by engravers in the preparation of their varnishes.

The existence of springs saturated with sulphuretted hydrogenous gas has been already alluded to. Such a spring near Mount All, called " the Pottery," attracted some attention in 1830, and it was examined by Dr. Doyle, Surgeon to the Forces, Drs. I. J. Ferguson, and R. C. Thomas. The first gentleman came to the conclusion, after a hasty examination, that the water in this spring, on the surface of which floated naphtha or green Barbados tar, resembled the water of the "Bain de l'Empereur" at Aix-la-Chapelle. Its odour was that of rotten eggs, and its savour not very disagreeable. Dr. Doyle was so forcibly struck with the great resemblance between them, that it appeared to him in tasting the water at the source, nothing was wanting but the caloric and air-bubbles of the waters of Aix to enable him to pronounce upon their identity. He considered that the waters of the Pottery spring possessed qualities of a rare and precious kind, and might. be beneficially employed for the cure of cutaneous maladies, as well as for those complaints termed obstructions

1 Dr. H. W. Hofmann, Professor at the Royal College of Chemistry in London, has been kind enough to analyse this gas. I subjoin his description :-"The gas is perfectly inodorous and colourless; it burns with a light bluish flame and without explosion. The absence of olefiant gas could be immediately seen from the appearance of the flame. The gas was tested for oxygen and for carbonic acid; for the former by small phosphorous balls, for the latter by potassa balls. Both these gases were found to be absent. The gas was analysed by the common eudiometrical process: oxygen was introduced into the gas deflagrated, and the carbonic acid formed, and absorbed by potassa; after which the respective volumes were observed. From these observations the gas was found to be pure light carburetted hydrogen (marshgas, fire-damp) CHI, containing one equivalent of carbon and two equivalents of hydrogen, or in 100 parts, there were 75 parts of carbon, and 25 parts of hydrogen."

2 Barbados Agricultural Reporter, vol. i. p. 179.

of the liver, spleen, bowels, &c1. The two medical gentlemen who accompanied Dr. Doyle were of a similar opinion. It appears from a letter addressed by Dr. Thomas to Mr. Abel Stuart, that there were five springs in the neighbourhood of Mount All and Vaughan's; namely, "a strong chalybeate (to the taste sulphate of iron), and an impregnation of Barbados naphtha; second (the Pottery), a sulphuretted hydrogenous water with a plentiful percolation of naphtha on its surface; third, a strong and simple chalybeate; fourth, a weaker ditto; fifth (looking over Vaughan's), a spring with the evident taste of sulphate of magnesia, and no doubt an aperient2. It is much to be regretted that these waters have not been analysed long ere this by some skilful and accurate chemist, as we must remain much in the dark about them until that is done."

The Barbados green tar, or petroleum, has been used with success in cases of leprosy. Mr. Abel Stuart petitioned the House of Assembly to erect upon Bird Island an hospital for the more convenient prosecution of his labours in the cure of leprosy by means of the green tar, and chiefly by the use of the waters from the spring called the Pottery, to which he ascribed similar qualities as the Harrowgate waters. He asserted that he had made his experiments chiefly upon cases of confirmed leprosy, and that in no instance had he failed to arrest the progress of the disease, even in its last stages. The object of the petition was not carried out, and I am not aware whether the virtue of the tar and the waters of the spring are really so efficacious as Mr. Stuart has stated. The beneficial effect of the naphtha in cutaneous affections is undoubted, and a kind of naphtha soap, under the name of Hendrie's Petroline Cosmetic Soap, is much in use in cutaneous diseases, and in cases of fine and tender skins. According to Dr. Andrew Ure, it contains from ten to twelve per cent. of petroleum, which, not being susceptible of saponification with alkali, retains its detergent and sanitary virtues upon the skin quite unimpaired. A patent medicine, under the name of Dr. Berkeley's Aromatic Tar Pills, was much in vogue some twenty years ago. It was asserted that Dr. Berkeley, Bishop of Cloyne, had introduced the tar in 1744, and recommended its qualities in numerous diseases. As usual with universal medicines, the aromatic tar pills were to cure every disease.

The clays, mixed more or less with siliceous matter, were formerly extensively used for the preparation of earthenware. The potteries were very numerous during the last century, when it was customary to manufacture forms for making clayed sugars. Goglets, pitchers, and some other coarse articles of pottery and ware, are still manufactured in the Scotland district.

The numerous Septaria might be used for the preparation of cement. Parker's cement is prepared out of a similar mineral, which is found in the London Clay.

'Dr. Doyle's letter to Mr. Caldecott.

2 It is used as such by the labourers in the neighbourhood.

The yellow and brown ochres, which are found in St. Andrew's and at Bissex Hill, are sometimes used as paints by the labourers.

The calcareous sandstones are extensively used for building materials, and the micaceous sandstone is well-adapted for the erection of chimneys and furnaces. It is usually called firestone in consequence of it. The calcareous conglomerates, composed of triturated minute fragments of shells, are used for dripstones, and those rocks which consist of more minutely comminuted shells, for building materials. This rock is quite soft when quarried, and may be cut into any shape. By exposure to the air, or by being washed by the sea, it assumes great hardness. The Mole Head is built of similar rock, which is quarried extensively near Highgate.

The productive soil which rests on the coralline formation is of a varied nature. On the higher table-land, as near Mount Wilton, Lyon Castle, and Castle Grant, is a soil of reddish-brown hue, which, according to Dr. Davy, contains a large proportion of a siliceous matter in a very finely divided state, with a certain portion of clay, and an admixture in small quantities of lime and magnesia1. Another quality of soil is that which prevails between the terrace elevations, as in the higher valley called Sweet Bottom, chiefly near the estates Sweet Vale and Redland. It contains more clay than the first-mentioned soil, and a large proportion of silica, but little lime and magnesia. Its colour varies between red and brown. A third variety of soil differs little from calcareous marl. It is incumbent on a substratum of marl, and consists of carbonate of lime, containing fragments of sea shells. It is generally of a light colour, and occurs especially on the north-eastern part of St. Philip's, in parts of St. Michael's, and also of St. Lucy's. A fourth variety is in some situations almost black, consisting of vegetable matter in a peculiar state of decomposition, approaching (as Dr. Davy believes) the state of peat3. It contains commonly a good deal of clay with a sufficiency of calcareous matter, and of silica and magnesia. It occurs in low situations towards the sea-coast. Dr. Davy mentions another variety of soil from Codrington Estate below the college. It is a calcareous argillaceous marl of a gray colour, consisting of alumina, carbonate of lime, and of silica in welladjusted proportions, with some carbonate of magnesia. The steep hills and ridges below the college, and their valleys and ravines, consist of such soil, which though barren in aspect possesses real fertility and abundance of water.

1 The greater part of these observations on soils are quoted from A Discourse delivered before the General Agricultural Society of Barbados on the 22nd of December 1846, by John Davy, M.D., Inspector-General of Army Hospitals.' Printed in the Barbados Agricultural Reporter, February 6th, 1847.

2 Some bluish clay is found near Sweet Vale on the road to Redland.-R.H.S. 3 I have received from Mr. Pile some dark black soil from the neighbourhood of Spring Garden, which has all the appearance of peat.-R.H.S.

Dr. Davy considers that the soils on the table-land and Sweet Bottom arose from the subsidence of drift-matter, brought by the currents when these parts were lying at a considerable depth in the ocean. He observes, that the red soil of the higher grounds presents itself at heights where it could not be brought after the ground on which it rests, namely, coral and shell limestone, was raised from the depths of the sea, because there is no higher ground near from which it could have been conveyed by the action of water. Dr. Davy describes a hill, the summit of which consists entirely of red clay, near Horse Hill, and there is another near Sugar Hill. Barbados does not offer a singular instance of red soil resting on coral limestone, which some geologists suspect to be the residue of the limestone exposed for ages to the dissolving action of rainwater.

I regret exceedingly that I carried no sample of this red soil with me, in order to send it to Ehrenberg for examination, whether it contains siliceous Polycystina. So much is certain however, that the red soils. from Sweet Bottom and from the road near Mount Wilton differ geòlogically in their age from those near the summit of Mount Hillaby; the former does not contain a single species of Polycystina, while the red soils from the northern declivity, near the summit of Mount Hillaby, contain several. These fossil animals are entirely peculiar to the rocks of the Scotland formation, which is of great importance in the relative judgement of their ages, if compared with the coralline formation. The numerous specimens of soil and mud, which I forwarded to Professor Ehrenberg, from several parts of the high table-land and the flats of St. Lucy's and St. Philip's, do not contain a single species of the cellular animalcules.


A SKETCH OF ORGANIC NATURE AS DEVELOPED IN BARBADOS. HEAT and light are the two great agents of nature which call organic life into existence; without it, those forms which now astonish us by their multiplicity would have remained inorganic substances. It is true we see in the rock a regular arrangement; we observe a gradual and laminated structure, and the crystal demands our admiration by its sym

metry; nevertheless, these forms extend only in one direction, resolvable in straight lines, while organic nature abounds in forms of endless varieties.

Where organic life has once been called into activity, be it represented by the smallest vesicle invisible to the naked eye or the majestic oak, there it will increase and augment under circumstances favourable to its further development. Nature never rests; vesicle is added to vesicle, cell to cell, and in organs of a higher degree follows fibrous tissue, the formation of which proclaims the first stage of vegetation. After the production of these fibres, other organs are successively produced; and, forced onward by the inert power of organic life, the plant ascends to its perfect form.

The rock, an inorganic substance, increases by the adhesion of new parts from without-it enters into several chemical and mechanical combinations, and may be divided into several parts alike in nature; but deprived of the power of reproduction, it remains a dead mass. And nevertheless, in that very power of reproduction which constitutes the great privilege of organic life, lies the germen of death.

Animals and plants form organic nature; they possess instruments of action on the action of each and their co-operation together depend their growth and perfection. They breathe by pores and absorb foreign substances. A derangement of their organs causes an interruption in their activity and produces ultimately death. Their reproduction is stipulated by natural laws. Only in the lowest stage of the vital activity, namely, in those organs which by their crystalline and fragmentary structure, by their straight lines or extension in one direction, remind us of inorganic substances, occurs a multiplying by spontaneous separation (Diatomacea). These microscopical bodies appear like the first dawn of organic nature-a stray ray of the all-animating sun called them into existence, ready to assume the form of vegetable or animal bodies. But even in the most imperfect state of organic bodies we find a combination of cells, a division in small organisms, and a reciprocal activity in the substances which compose their organization.

It was formerly asserted that the difference between inorganic substances and organic bodies, and between plants and animals, consisted in the following character:-" Inorganic bodies or rocks are without vitality, and of a similar structure throughout their extent; they increase by juxta-positio, and do not multiply by reproduction. Organic bodies are of dissimilar structure, increase by intus-susceptio, and multiply by reproduction. Without voluntary motion and stomachs they are called plants; with a will and motion and a stomach, animals1."

Our advanced knowledge proves that these limits are not so sharply drawn by nature as to permit the assertion, here ends animal life, and

1 Linnæus expressed the difference between inorganic substances and organic bodies, and plants and animals in the following short sentence: Lapides crescunt— Vegetabilia crescunt et vivunt-Animalia crescunt, vivunt et sentiunt.

« PreviousContinue »