The different forms of fruit, and also of vegetables, owe their great value to the fact that they possess powerful anti-scorbutic properties.  It will be best and simplest to define the word “anti-scorbutic” as “good against the scurvy.”  This latter disease is notably dependent on a want of fresh fruit and vegetables in the dietary, and consequently is more often observed amongst sailors; and though accessory conditions, such as great privations, bad provisions, or unhealthy surroundings, may predispose to it, yet that which essentially produces it is the deficiency of the former articles from the food.  At the present time it is not nearly so frequently seen, since, according to the mercantile marine regulations, subject to legislative enactments passed in 1867, in lieu of vegetables, one ounce of lime juice, sweetened with the same quantity of sugar, must be served out to each man daily.

In scurvy there is some great change effected in the blood, and it is as well to refer briefly to the characters possessed by the latter.  The blood as it exists in the body is a red alkaline fluid, having a saltish taste and possessing quite a noticeable odour.  It consists of minute bodies, the corpuscles, immersed in a liquid, the liquor SANGUINIS.  Salts also enter into its composition, and include the chlorides of potash and soda; the phosphates of lime, magnesia,-and soda; the sulphate of potash, and free soda.  Of these the salts of soda predominate, and the chloride—­that is, common salt—­is usually in excess of all the others.  The uses of these salts in the blood are to supply the different tissues with the salts they respectively require, to take part in maintaining the proper specific gravity and alkaline character of the blood, and to prevent any changes going on within it.

In scurvy, as mentioned before, the blood seems to undergo some great change, and there are accumulations of it beneath the skin.  The gums become spongy, bleeding on the slightest touch, and the teeth frequently loosen.  Blood often flows from the mouth and nose, or is vomited from the stomach, or is passed through the bowels.  Dr. Garrod advanced the view that scurvy was dependent on a deficiency of potash in the stem, and that vegetables which contained potash supplied the want.  It is questionable, however, whether the disease is due to this fact alone, since beef tea, which contains a good deal of potash, may be given freely to a scorbutic patient, yet he fails to recover till proper anti-scorbutic diet is supplied.  Dr. Ralfe found by experiments that when acids are injected into the blood, or an excess of acid salts administered, the same changes occur in the blood as in scurvy.  Hence he supposes that the latter disease is caused by a decrease in the alkalinity of the blood, which results from the absence of fruit and vegetables from the food.