Nevertheless, the eighteenth century nearly closed before the English government were roused to action in the matter. To Sir Gilbert Blane is due the honour of inducing the Admiralty to furnish a supply of lime-juice to all ships of the royal navy, especially those starting on long voyages. The effect was wonderful. The records of the Royal Naval Hospital at Haslar, near Gosport, shewed that one thousand four hundred and fifty-seven cases of scurvy were admitted in 1780, whereas in 1806 there was only one single case; the introduction of lime-juice as a regular item in ships' supplies having taken place in the intervening period. Scurvy became quite a rare disease on shipboard; and many ships' surgeons are said to have advanced towards middle life without having seen an instance of it. When Captain Parry organised his expeditions to the icy regions, he was sedulously attentive to this as well as to all other matters connected with the health and well-being of his crews. As he found that some of his men occasionally shirked the lime-juice given out to them, he adopted the plan of mustering them every day, and seeing that every one drank off his due allowance.
When the juice has been obtained by the aid of a screw-press or any other means, it is heavy, cloudy, and sour. A proportion of ten per cent. of spirit is added to preserve the juice from being too much affected by tropical heats, and also to modify the possible effect of too great acidity. The mixture is carefully bottled for sea-use; and the sailors and marines begin to drink it about a fortnight after leaving port. About an ounce a day per man is the usual allowance, often mixed with sugar in their grog; the quantity is increased if any symptoms of scurvy make their appearance. Lime-juice may be preserved in the same way as ripe fruits by placing the bottles containing it in water, boiling for half an hour, gradually cooling, and hermetically sealing. Dr Leach, consulted by the Board of Trade, strongly recommended the use of lime-juice in all emigrant and other passenger ships, and drew up a dietary scale for this purpose. An act of parliament had before that date been passed, directing the adoption of this medicament in the mercantile marine; but the lime-juice supplied by contractors was found to be frequently so grossly adulterated that scurvy began to appear. Whereupon a further statute ordered that all lime-juice should be officially inspected before being placed on shipboard. One ounce daily per head is now a pretty general allowance in all ships alike. The better class of passenger-ship owners, such as Messrs Wigram, had long before adopted the system, without waiting for any official pressure.
It is now, to sum up, admitted beyond doubt or cavil, that lime-juice is the most valuable of all known agents for warding off scurvy, or for curing when the disease has made its appearance.
In an earlier paragraph we briefly adverted to the fact that a Committee is officially examining into the circumstances connected with the outbreak of scurvy in the Alert and Discovery. Of course no attempt will be made here to anticipate the result, nor to pronounce an opinion on the question involved. But Captain Sir George Nares has himself made public some remarkable observations on the matter, revealing facts never before so fully known to those who are most directly interested in the subject. In a speech delivered at Guildhall, the gallant officer said: 'No sledge-party employed in the Arctic regions in the cold month of April has ever been able to issue a regular ration of lime-juice. Every commander has desired to continue the daily issue while travelling, as recommended by medical authorities; but all have failed in doing so during the cold weather. In addition to the extra weight to be dragged that its carriage would entail, there is the more serious consideration of the time and fuel necessary to melt it.... After the middle of May, when the weather is warmer, lime-juice can be (and was) used as a ration. Of course hereafter lime-juice in some shape or other must be carried in all sledging-journeys; and I earnestly trust that some means will be found to make it into a lozenge; for as a fluid, there is and always will be extreme difficulty in using it in cold weather, unless Arctic travelling is considerably curtailed. Owing to the thaw which sets in before the return of the sledges, in its present state it must be carried in bottles; but up to the middle of May it remains frozen as solid as a rock. If the bottles have not already been broken by the jolting of the sledge or the freezing of the contents, they have to be broken on purpose before chipping off a piece of the frozen lime-juice, as if it were a piece of stone.' Cannot our pharmaceutical chemists come to the rescue, and devise some mode of making lime-juice into small convenient lozenges or dry confections?
['BELL-ANIMALCULES.']
As we write, we look upon a prospect which excites our wonder and interest. The eye sees a variety of form and structure presenting a combination of grace and delicacy hardly to be matched in the whole of Nature's domain. Within the compass of a small round disc or circle, we behold numerous beings, each consisting of a bell-shaped head mounted on a delicate flexible stalk. The margins of the bells are fringed with minute processes, resembling miniature eyelashes, and hence named cilia; and these processes wave to and fro with an incessant motion, by means of which particles of solid matter suspended in the water around are swept into the mouth of the bells. Suddenly some impulse moves the beings we are gazing upon to contract themselves, and as if by magic, and more quickly than the eye can follow them, the bell-shaped bodies shrink up almost into nothingness by the contracting power of their stalks. Soon, however, as the alarm disappears, the beings once more uncoil themselves, the stalks assume their wonted and straight appearance, the little cilia or filaments once again resume their waving movements, and the current of life proceeds as before.
The spectacle we have been describing is not by any means a rare or uncommon one, to the microscopist at least. We have merely been examining a tiny fragment of pond-weed and its inhabitants, floating in a thin film of stagnant water. Attached to the weed is a colony of those peculiar animalcules known popularly as 'bell-animalcules,' and to the naturalist as Vorticellæ. Yet common as the sight may be to the naturalist, it affords one example of the many undreamt-of wonders which lie literally at the feet, and encompass the steps of ordinary observers; and it also exemplifies the deep interest and instruction which may be derived from even a moderate acquaintance with natural history, together with the use of a microscope of ordinary powers.
The bell-animalcules are readily procured for examination. Their colonies and those of neighbour-animalcules may be detected by the naked eye existing on the surface of pond-weeds as a delicate white nap, looking like some lower vegetable growth. And when a portion of the weed is placed under the object-glass of the microscope, numerous animalcules are to be seen waving backwards and forwards in all their vital activity. The general appearance of each animalcule has already been described. The bell-shaped structure which, with its mouth turned uppermost, exists at the top of each stem or stalk, is the body. The stalk is never branched in these animalcules; and except in certain instances to be presently alluded to, each stalk bears a single head only. The structure of the stalk is worthy of special mention. The higher powers of the microscope shew us that within the soft substance or protoplasm, of which not only the stalk but the body also is composed, a delicate muscular fibre is contained. This fibre possesses the power of contracting under stimulation, just as the muscles of higher animals contract or shorten themselves. And by means of this structure therefore, the bell-animalcules, when danger threatens them, are enabled to contract themselves with great rapidity, the stalk itself shrinking up into a spiral form. The operation reminds one forcibly of some sensitive plant shrinking when rudely touched. The lower extremity of the stalk forms a kind of 'root,' by means of which the animalcules attach themselves to fixed objects, such as pond-weeds, &c.
The bell-shaped body is sometimes named the calyx, from its resemblance to the structure of that name in flowers. The edge of the bell possesses a very prominent rim, and within this we find the fringe of filaments or cilia, which in reality form a spiral line leading to the edge of the bell, where at one point is situated the mouth, represented by an aperture or break in the rim of the body. We have seen that the cilia create miniature maëlstroms or whirlpools in the surrounding water, which have the effect of drawing particles of food towards the mouth. The study of the bell-animalcules affords an excellent example of the gaps which yet remain to be filled up in our knowledge of the structure even of the lowest and commonest forms of life. No structures are more frequently met with in the animal world than the delicate vibratile filaments or cilia, so well seen in the bell-animalcules. The microscopist meets with them in almost every group of animals he can examine. They are seen alike in the gills of the mussel and in the windpipe of man; and wherever currents of air or fluid require to be maintained and produced. Yet when the physiologist is asked to explain how and why it is that little microscopic filaments—each not exceeding in many cases the five-thousandth part of an inch in length, and destitute of all visible structure—are enabled to carry on incessant and independent movements, his answer is, that science is unable, at the present time, to give any distinct reply to the query. No trace of muscles is found in these filaments, and their movements are alike independent of the will and nervous system; for when removed uninjured from the body of the animal of which they form part, their movements may continue for days and weeks together. What a field for future inquiry may thus be shewn to exist, even within the compass of a bell-animalcule's history—these animalcules being themselves of minute size, and even when massed together in colonies, barely perceptible to the unassisted sight!