Imatges de pÓgina
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ties, (in which state they will exist in the mineral water, at least in the greatest proportions,) we find

the Bath water

*

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* to contain

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In

1000 gr.

1 pint, (34.659 cub. inch.) 1.89031

0.21560

0.19018

1.66744

0.04173

0.36588.

0.27618 2.42145
1.16371 10.20303
0.15208 1.33339

0.00347

0.00215

0.04610

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Chloride of Sodium

1995

Magnesium
Sulphate of Potassa

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99

Carbonate of Lime

Proto-carbonate of Iron

Alumina

Silica

Extractive matter

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Soda

Lime

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Chloride of Sodium

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Magnesium

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Sulphate of Soda

99

Lime
Carbonate of Lime
Proto-carbonate of Iron

Silica

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In distributing the acids and bases, there remains a surplus of 0.01827 of carbonic acid. The processes by which the different bases were separated being more complicated, it is to be expected that the loss which they sustained is proportionably greater than with the acids. Besides, the determination of the carbonic acid itself is less certain than that of the other constituents, on account of the comparatively small quantity employed for the experiment, and the simplicity in transferring measure into weight.

The re-action which tincture of galls produces in the mineral
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* The results of this analysis differ, at the first appearance, very much from those obtained by Dr. Scudamore, the cause of which is the different theoretical view which the Doctor has followed in computing the binary combinations. Having transferred the data of Dr. Scudamore into equivalents, according to the greatest mutual affinities, I subjoin a table of his analysis, computed for the same quantity of the mineral water (34.659 cub. inch.), in order to facilitate a comparison.

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2.09120 gr. 18.33496 gr.

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water, just drawn from the pump, is slighter than we could anticipate it to be, according to the proportion of iron found by the analysis: the cause of which, however, is, that a part of the iron is precipitated instantaneously, when the mineral water, by pumping and pouring into the tumblers, mixes with the atmospheric air. It is therefore merely suspended in a very minutely divided state, (probably in the form of a silicate,) and has no effect on the re-agent, which is only acted upon by that portion of iron which is present in a state of solution.

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~Analyses of two Mineral Springs in Windsor Forest.

Captain F. Forbes of Winkfield Place, Windsor Forest, discovered, some time ago, two mineral springs on his estate; one, the analysis of which is stated under A., in the immediate neighbourhood of his mansion; the other, mentioned hereafter under B., at some distance. Both these mineral springs, belonging to the magnesio-saline class, have since been used, as I am informed, by a great number of patients; and the good effects which have been observed from their use have induced Captain Forbes to build a pump-room for the accommodation of the public.

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The mineral waters which were sent to my laboratory for chemical examination were colourless, almost perfectly transparent, and without smell. If exposed to the air in an open vessel, they very soon covered the sides of the glass with a precipitate of carbonate of lime. Boiling produces a very copious earthy precipitate. Slightly reddened litmus paper is turned by them into blue; the carbonic acid gas, which they yield by boiling, must therefore be considered entirely to exist in them in union with the earthy carbonates, forming bicarbonates.

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Both mineral waters were examined in a similar way to the Bath water; and the results of their analysis gave their constituents as follows:

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A Letter to Mr. BAILY, admitting his undisputed Claim to a Theorem relating to SURVIVORSHIPS. By a Correspondent.

DEAR SIR,-I have been thinking, that, as an attempt has been made to direct the public attention to the oversight which I acknowledged to you the moment that I was aware of it, it might be right that I should ask you, whether there was any form, or any channel, by which you would like that I should publicly admit your undisputed claim to the discovery which I have lately printed in capitals as my own: and to assure you, that you cannot be more willing to point out such a proceeding than I should be to comply with your wishes.

I have certainly given you an advantage, in printing, as a conspicuous part of my paper, a remark which you had only thought worthy of being inserted in a note; and for myself, the circumstance has been a little unlucky, not from any censure that may have been passed on me, as not having read every note even in the best book relating to the general subject of my essay; and still less from the contemptible sus

picion of my having made a childish attempt to deck myself in borrowed plumes, and then to hold them so high that the slightest breath would blow them away: but because the occurrence tends to divert the attention of a reader from the essential subject of my essay; which, you may have observed, is, first to establish the superior convenience of a good formula in preference to all tables formed from a limited observation, for all ordinary cases of the valuation of annuities; that is, between the ages of ten and seventy: and, secondly, to show, as I may hereafter do still more fully, that a uniformly increasing decrement of survivors, throughout the middle of life, will afford a value of mortality sufficiently near to the results of tables the most discordant among themselves, provided that the rate of increase be properly adjusted to the table.

I am, dear Sir,

Your faithful and obedient servant, Waterloo Place, 1 Feb. 1829.

On the Atmospheric Influence of Woods.

THE effects produced on climate, by the preservation or destruction of forests, is an interesting subject of inquiry, which has sometimes engaged the attention not only of philosophers but of legislators. In France, about forty years ago, some alarm was created on account of the rapid cutting down of woods which had then changed owners, or were less carefully protected than they had formerly been. Where wood forms a great part of the fuel of a country, a strong motive will always exist for the planting of trees, and for guarding against their wasteful removal. But another evil than the deficiency of firewood, was then apprehended. It was contended by Cadet de Vaux, and other writers, that the great droughts experi enced in some districts, were caused by the absence of the trees, which used to attract the clouds, and thus conduct to the earth those fertilizing showers, which reward the labours of the husbandman with an abundant harvest. Amidst the agitations of the Revolution, the complaints of these writers were listened to, and their representations were more than once brought under the consideration of the Convention and

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the Council of Five Hundred. We do not precisely recollect what legislative measures were adopted; but we believe, among other things, the sale of the National Forests was stopped. However, it does not appear that what was then done, though it may have saved some of the property in the possession of the state, had any important effect on the whole. Indeed it will be seen from what follows, that since that period, the woods of France have sustained a considerable diminution, equal in extent to the difference between and of the territory. 1 qoof.boGAT

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. DEDESTINY

In the mean time, the investigation of this interesting subject has not been neglected. The attention of naturalists and men of science in the Netherlands was, in the course of last year, called to the alterations produced in the physical state of countries, by the destruction of forests, in consequence of a prize for the investigation of this important question, being offered by the Royal Philosophical Society of Brussels. The essay which obtained the prize, was written in French by M. A. Moreau de Jonnes, a staff-officer in the army. It appears that the author does not altogether concur with M. Cadet de Vaux; but we have not seen the original, and the following account has reference to a German translation, by M. Widenmann, Professor of Natural History, at Tubingen. In Germany, where great importance is attached to the subject, the work of M. Moreau de Jonnes has been, upon the whole, very favourably noticed by the reviewers of that country, and we have taken the liberty to make use of some of their observations. T ...The author begins with a statistical account of certain woods and forests, from which, though he complains of the insufficiency of the documents available for his calculation, at least one conclusion, which appears pretty well founded, may be drawn. According to the data here made use of, the woods in France amounted, in 1750, to more than a fourth of the surface of the whole country; in 1788, to a seventh; and in 1814, to not quite a twelfth of that surface. Thus, within sixty-four years, 5000 square miles of the woods of France must have disappeared. In England, according to the author's estimate, the woods amount to only one twenty-third of the surface.

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