The appearance of extraordinary spots on the sun has attracted a more than ordinary degree of attention to that luminary, and to Mr J. Nasmyth's 'views respecting the source of light,' which, though published a few months since, are now again talked about. Mr Nasmyth, after several years' observation, comes to the conclusion, 'that whatever be the source of light, its production appears to result from an action induced on the exterior surface of the solar sphere;' and he believes it reasonable to 'consider the true source of the latent element of light to reside, not in the solar orb , but in space itself; and that the grand function and duty of the sun is to act as an agent for the bringing forth into vivid existence its due portion of the illuminating or luciferous element; which element he supposes to be diffused throughout the boundless regions of space, and which in that case must be perfectly exhaustless. Further, assuming this luciferous element to be not equally diffused through space, we find a reason why in some ages of the earth's history the heat should have been greater than at others, why stars have been seen to vary in brightness, and why there was that puzzle to geologistsa glacial period. During that period, according to Mr Nasmyth, with whose words I finish this part of my communication, 'an arctic climate spread from the poles towards the equator, and left the record of such a condition in glacial handwriting on the mountain walls of our elder mountain ravines, of which there is such abundant and unquestionable evidence.'
Our Microscopical Society have made a discovery in an all but invisible subject: they now state the Volvox globator to be a vegetable, and not, as has long been supposed, an animal, as its cells, presumed to be ova, are produced in the same way as in certain kinds of algæ . In the discussion excited by this announcement, it came out that several other minute forms, classed by Ehrenberg among living animalcules, are in reality vegetable; which, if true, shews that a good deal of microscopical work will have to be done over again. The Syro-Egyptian Society, too, have heard something relating to the same subjecta paper on Ehrenberg's examination by the microscope of the anciently deposited alluvium of the Nile, from which it appears that 'microscopic animals' in countless numbers were the cause of the remarkable fertility of the soil, and not vegetable or unctuous matters. Talking of deposits reminds me of a little fact which I must not forget to mentionthe finding of a fossil reptile in the 'Old Red' of your county of Moray is, barring the alarm, as much a cause of astonishment to our geologists, as was the mark of the foot on the sand to Robinson Crusoe.
Now for a few gatherings from the continent. M. Chalambel has laid before the Académie at Paris a 'Note on a Modification to be introduced in the Preparation of Butter, which improves its Quality and prolongs its Preservation.' 'If butter,' he observes, 'contained only the fat parts of milk, it would undergo only very slow alterations when in contact with the air; but it retains a certain quantity of caseum , found in the cream, which caseum, by its fermentation, produces butyric-acid, and to which is owing the disagreeable flavour of rancid butter. The usual washing of butter rids it but very imperfectly of this cause of alteration, for the water does not wet the butter, and cannot dissolve the caseum, which has become insoluble under the influence of the acids that develop themselves in the cream. A more complete separation would be obtained if these acids were saturated; the caseum would again be soluble, and consequently the quantity retained in the butter would be almost entirely carried away by the washing-water.'
The remedy proposed is: 'When the cream is in the churn, pour ina little at a time, and keep stirringenough of lime-wash to destroy the acidity entirely. The cream is then to be churned until the butter separates; but before it forms into lumps, the buttermilk is to be poured off, and replaced by cold water, in which the churning is to be continued until the butter is complete, when it is to be taken from the churn and treated as usual. I have,' says M. Chalambel, 'by following this method, obtained butter always better, and which kept longer, than when made in the ordinary way. The buttermilk, deprived of its sharp taste, was drunk with
pleasure by men and animals, and had lost its laxative properties.' By means of lime-wash or lime-water, he has restored butter so 'far gone' that it could only have been recovered by melting; but any alkaline lixivium will answer the same purpose.
I have more than once kept you informed of the inquiry concerning the effects of iodine on the human system, which has so long engaged the attention of several eminent chemists on the continent; and now have to report something further by M. Fourcault, whose communication thereupon to the Académie is entitled, 'On the Absence of Iodine in Water and Alimentary Substances, considered as Cause of Goître and Crétinism, and on the Means of Preventing the Development of these Affections.' He has investigated the subject profoundly and analytically, and concludes that 'the absence or insufficiency of iodine in water and in alimentary substances, is to be considered as the primitive cause, special or sui generis , of goître and Crétinism;' that the existence of the diseases does not depend on the presence more or less of sulphate of lime or magnesia in the animal economy; that 'iodine acts in goître as iron in chlorosisby restoring to the system one of its essential principles;' and that 'the most powerful secondary or auxiliary causes are: a coarse and uniform vegetable regimen; living at the bottom of deep, enclosed valleys; in low and damp houses, into which air and light penetrate with difficulty; the alliance of infected families among themselves; and the want of such employment as would yield a comfortable subsistence and proper development of the physical forces.' In commenting on these statements, Baron Thénard observed that M. Chatain, in the course of his able researches on iodine, had analysed the waters of those Alpine valleys most subject to goître, and found that mineral almost entirely wanting. And it has been proved that sea-salt, containing a minute quantity of ioduret of potassium, acted as a preservative from goître on all the inhabitants of a district who made use of it. The air, too, has been examined as well as the water, and, so far as yet ascertained, the proportion of iodine in the atmosphere is variable, and much greater in amount in some regions than in others. The activity prevailing in this particular branch of inquiry is the more encouraging, as the maladies which it aims at removing are of so peculiarly distressing a nature; and the investigation is one likely to lead also to valuable incidental results.