Barley is a spicated, oblong, ventricose seed, pointed at each end, and marked with a longitudinal furrow. The essential constitution of the parts, in all plants, says Dr. Grew, is the same: thus this seed, like those which have lobes, is furnished with radical vessels, which, having a correspondence with the whole body of the corn, are always ready, when moistened, to administer support to the plume of the embryo, usually called the acrospire. These radical vessels, at first, receive their nourishment from a great number of glandules dispersed almost every where in the grain, whose pulpous parts strain and refine this food, so as to fit it to enter the capillary tubes; and such an abundant provision is made for the nourishment of the infant plant, that the same author says, these glandules take up more than nine tenths of the seed.

Barley is sown about March, sooner or later, according to the season or soil that is to receive it, and generally housed from ten to twenty weeks after. Most plants, which so hastily perform the office of vegetation, are remarkable for having their vessels proportionably larger; and that these may be thus formed, the seed must contain a greater quantity of tenacious oils, in proportion to those seeds, whose vessels being smaller, require more time to perform their growth and come to maturity. This grain, as may be observed, grows and ripens with the lower degrees of natural heat; from whence, and from the largeness of the size of its absorbent vessels, it must receive a great portion of acid parts. It is said to be viscid, though, at the same time, a great cooler, water boiled with it being often drunk as such; and, however it be prepared, it never heats the body when unfermented.

From these circumstances, of its being viscous and replete with acids, it would at first appear to be a most unfit vegetable, from which vinous liquors, to be long kept, should be made; and, indeed, the extracts from it, in its original state, are not only clammy, but soon become sour.

When the grain is at full maturity, its constituent parts seem to be differently disposed than when in a state of vegetation. By germination alone all its principles are put in action; the fibrous parts possess themselves of a great quantity of tenacious oils, leaving the glandules and finer vessels replete with water, salts, and the purest sulphur. If, in this state, the corn is placed in such a situation, that, by heat, the acid and watery parts may be evaporated, the more such heat is suffered to affect it, the more dry, and less acid, will the corn become; its parts will be divided—its viscidity removed; its taste becomes saccharine, by the acids being sheathed or covered over with oils; and these last be rendered more tenacious in proportion to the greater quantity of heat they are made to endure. This process, regularly carried on, is termed malting, and will hereafter be explained more at large.

But, before we enter thereon, it is necessary to consider the state of the grain as it comes from the field.—When mowed, though, upon the whole, it may be said to be ripe, yet every individual part, or every corn, cannot be so. In some seasons, this inequality is so remarkable, as to be distinguished by the eye. The difference in the situation, the soil, and the weather, the changes of the winds, the shelter some parts of the field have had from such winds, are sufficient to account for this, and a much greater variety. When the greater part of the corn is supposed to have come to maturity, it is cut and stacked; the ripest parts having the least moisture, and the fewest acids, as the greenest abound in both. In this state the unripe grains of the corn communicate, to such as are more dry, their moisture and acid parts, which, coming in contact with their oils, an agitation ensues, more or less gentle, in proportion to the power of the acids and water; and from hence is generated a heat, the degree whereof is with difficulty determined.

When this sweating in the mow is kept within its proper limits, the whole heap of the corn, after this internal emotion is over, becomes of one equable dryness, and is not discoloured; but if the grain be put together too wet or too green, the effervescence occasioned thereby will produce such a violent intestine heat, as to charr and blacken the greatest part thereof, nay often make it burst into actual flame.

The effect which a moderate and gentle heat has on the corn, is that of driving the oils towards the external parts of its vessels and skin: by this means, it becomes more capable to preserve itself against the injuries of the weather. The more it is in this state, the backwarder will it be to germinate, when used to this purpose; and if this act is carried too far, or to somewhat like what we have just now mentioned, the plume and root of the enclosed embryo must be scorched, the corn become inert, and incapable of vegetation. This effect is produced by a motion sufficient to remove the particles of the grain from each other beyond their sphere of attraction; and the heat, by which this motion is excited, has been found, in malted corn, to be at about 120 degrees.

It is likely, that vegetables, in general, are susceptible of a large latitude in this respect, according to their different textures. The degree of heat just now mentioned may, perhaps, be applicable to barley alone; the seeds of some grapes endure 126 degrees of heat, and may be capable of being impressed with more, and yet vegetate. But, with corn, if their oils have endured so great a heat, as thereby to be discolored, the seed can by no means be revived. The color of the grain properly indicates the healthy state of the embryo, or future plant; but this, more immediately, is the business of the farmer and maltster, than that of the brewer.

Thus, though it may be disadvantageous to the maltster to steep grain which has not sweated in the mow, as, for want of this, it will not equally imbibe the water; so barley, that is over-heated, or mow burnt, cannot be fit for his purpose. It is, in fact, scarcely possible that any large quantity of barley, from the same stack, should make equally perfect malt, as, on its being put together, the heat generated is always greatest in the centre of the rick, and considerably more there than in its exterior parts.