uncrystallizable portion becomes condensed by desiccation, and may be rendered almost solid; in which case it is impracticable to separate the sugar without reducing the mass with warm water, and this is necessarily attended with the dissolving of a portion of the solid sugar.

Many different modes of draining sorghum sugar have been suggested, and several have been patented and extensively sold through the country. In con nexion with these, a great number of (so-called) processes for "making sugar from sorghum" have been introduced. Enormous sums have been paid by producers for these so-styled "processes." Space will not permit them to be referred to separately, but this paper would be incomplete if it failed to warn sorghum-growers, and all who are interested in the subject, against the absurd pretences and fraudulent practices of these peddlers of "rights" for making sorghum sugar. Not one of the processes for making sugar from sorghum, or for draining sorghum sugar, which has been patented and sold since the introduction of the plant, contains a single essential element of novelty. All, without exception, consist of either slight and immaterial variations from processes which formerly existed and belonged to the public; or, if they present elements of novelty in the form of agents and substances not formerly used, they are, in all cases, not only non-essential and useless, but often absurd, and not unfrequently positively injurious. And yet for these miserable pretences sorghum-growers of the country have paid, at a moderate estimate, not less than four hundred thousand dollars. This is not the place to explain how it is that patents are obtained for trivial and useless inventions. It may, however, be remarked that a large proportion of all the patents issued are for really worthless inventions, or for trifling and unimportant modifications of that which was formerly known. But a patent covers only that which is found by the office to be new, and this may be an immaterial part of all that the applicant describes in his specification. An old and well-known process may be changed by adding another element, or slightly modifying those which formerly existed, so as to produce a new process, but the change may be no improvement-it may produce no difference whatever in the effect; still it is a new process, and the applicant, if he swears that he believes his alleged invention to be "useful," is entitled to and can claim letters patent for it. The letters patent, however, cover, as has been said, only that which was new. They cannot deprive the public of that which was formerly public, and cannot give to a patentee anything more than he has invented. This brief explanation seems to be required in this connexion, as the opinion prevails somewhat that the broad seal of the Patent Office granted to an inventor implies that the august head of that department, and the entire government through him, certifies to the great value of any patented invention, and to the truth of all the patentee has been pleased to say about it. This popular superstition is of great service to dealers in worthless patents, for it predetermines a thing patented to be new and valuable, and this causes purchasers to neglect to examine and scrutinize the merits of an invention.

The operation of draining should always be performed in a warm room, and the temperature of the sugar to be drained should be about blood heat, if it can be brought to that temperature slowly without the application of fire directly to the mass. If sorghum sugar crystallizes out of a solution not very dense and waxy, it may be transferred to moulds for draining. These may consist of vessels of any convenient size and shape. Cone-shaped vessels are most commonly used. The arrangement of them should be such as to allow them to be filled, and, after standing a few hours (perhaps days) until the sugar "sets," a plug can be withdrawn from the bottom to allow the molasses to come off. It will frequently happen that molasses refuses to separate from the sugar. When the plug is withdrawn, both come off together. This mode of draining can only be applied to sorghum sugar under the most favorable circumstances. It will

rarely present itself in a condition to be thus treated, and other means must be resorted to. Among the many which have been used are the following:

Place the mush sugar in a coarse cloth or bag, and suspend it until the molasses drips away. After the dripping ceases, the sugar may be thoroughly mixed with a very small quantity of water and again hung up to drain; and this may be repeated, if desired, until the sugar becomes nearly white, though the operation will be attended with some loss of sugar by dissolving. Another mode consists in enclosing the mush sugar in bags and subjecting it to pressure. After once pressing, the sugar may be mixed thoroughly with a small quantity of water and re-pressed, repeating as many times as may be necessary or desirable. This is a very old process, but, like many other old processes, has been re-invented, and "rights" to employ it have been extensively sold. The most appropriate and effectual means of draining sorghum sugar is by the centrifugal process. This has been used in the tropics for many years, and is an old process, although it has been made the subject of several new patents for Fo-called improvements, and an attempt is made to establish a monopoly of the right to drain sugar by centrifugal means. It is a public right, and any ordinary mechanic can construct a machine, on a small scale, adapted to the work. The machine consists of a cylindrical screen, carried usually by a vertical shaft revolving at a high velocity. The speed should be nearly as great as would be appropriate for a circular saw of corresponding diameter. An outer case surrounds the screen. The mush sugar is placed in the screen, either when in motion or at rest, care being taken to distribute it evenly around upon all sides. The sirup or liquid portion is caused to force itself out through the meshes of the screen by the centrifugal action, and is caught in the outer case, from which it should be conducted away by a spout. A small machine, with a screen twelve inches in diameter and six inches deep, can be made to run by hand, though the speed must be high, and the work of draining by hand is necessarily laborious. The quantity which a hand machine is capable of draining in an hour depends upon the condition of the sugar. Two or three times as much power is required with sugar in one state as in another; and sometimes it is found impossible to produce any separation by the centrifugal, without adding considerable water and greatly reducing the viscid, adhesive medium in which the sugar is contained. It is perhaps safe to say that with a light-running hand machine and a fair quantity of mush sugar, from fifteen to twenty pounds of dry sugar per hour may be produced.

CONCLUSION.

The production of sugar from sorghum has been much retarded by a false notion on the part of many, that it is to be accomplished by some sovereign specific, which is to make the sirup crystallize. This has led producers away after pretentious patent processes, to the neglect of a careful attention to every step in the operation, which is the only certain means of success, and without which nothing else is of any avail. It should be understood that sirup frequently contains no crystallizable sugar whatever, and to produce a single grain of true sugar from such sirup transcends all arts of man's device. Carbon has been made to crystallize and afford artificial diamonds, but no man has ever yet succeeded in making a grain of artificial cane sugar. It is developed alone the great laboratory of nature, and all that art or science can do is to preserve it unimpaired, and separate it from excess of water and the impurities which obstruct granulation. It will then crystallize, when reduced to the proper temperature, without the employment of any "process" or extraneous aids whatever. Sirap often contains so small a portion of crystallizable sugar-that is, the minute atoms of sugar are so far separated, that they are not attracted to each other; in which case crystallization cannot occur. Sorghum sirup gene

rally contains a dense, viscid substance which obstructs granulation. This can be removed; but the only effectual means of removing it is by filtering it through a liberal quantity of freshly burned bone-coal-a means which cannot be considered practicable with the mass of farmers. But it can be, in a great measure, avoided or prevented from occurring; and this, together with the means to be employed for promoting the development of cane sugar in the plant and preserving it unimpaire 1 constitutes the whole art of "making sugar from sorghum. It all consists in strict compliance with the conditions imposed at each step in the operation, from the selection of the seed to the final act of purging or draining the crystallized product. It is not to be accomplished by any magical or sleight-of hand process. There is absolutely no "royal road" to sugar.

THE GRAPE DISEASE IN EUROPE;

ITS

ORIGIN, HISTORY, PHENOMENA AND CURE,

BY HENRI ERNI, M. D., DEPARTMENT OF AGRICULTURE.

The grape disease being with us a growing evil, threatening the total destruc tion of some of our native American varieties of vines, like the Catawba, I have deemed it important to give a brief history of the destructive malady which has prevailed of late in European vineyards, hoping it may to some extent aid in understanding the character of discases of the grape which are beginning to prevail in this country.

The literature upon the subject of grape disease is meagre. The books consulted in writing the following article were, principally: Louis Leclerc, Les vignes maladé, report to the minister of the interior, Paris, 1853. The plates annexed were copied from this report. Dr. H. Schwartz, Chemie und Indus trie unserer Zeit; Breslau, 1862. Dr. W. Hamm's Weinbuch, Leipzig, 1865. Marès diseases of the wine stock, in "Memoires de la Société Impériale et Centrale d'Agriculture." An extract of the above, in Journal de Pharmacie et de Chemie, Mai, 1857, p. 355; also, in Dingler's Polytechnisches Journal, Bd. cl., 1858, pp. 148-153. J. T. A. Barral: Cure of the vine disease, with instructions how to apply sulphur, and figures of the apparatus, from "Extrait du Journal d'Agriculture Pratique," No. du 20 Juin, 1857. Paris, Librarie Agricole de la Maison Rustique rue Jacob, 26.

The year 1845 will ever be a painfully memorable one, by giving birth to two new diseases which threatened the entire destruction of the potato and wine crop, and which caused suffering, devastation, and pecuniary ruin to an incredible extent on the continent of Europe.

It would require a great deal of space even to allude to the different theories and opinions advanced as to the cause of these diseases. Suffice it to state, that time has proved the majority of them to be fallacious. All such as imputed to peculiar electric conditions, a wet season, or other meteorological influences, and in seasons remarkable for dryness, are manifestly refuted, whilst the gradual accumulation of scientific facts has established, almost beyond dispute, that the potato and wine diseases are not only accompanied by, but result from, fungus or mouldy growths. Limiting our remarks here more particularly to the wine disease, we begin with its

HISTORY.

In the spring of 1845 this disease was observed for the first time in Kent England, on vines raised in the hothouse of Mr. Tucker. The termination of the young shoots assumed, first, a crispy look, began to wither, and then dried up. The unripe grapes were next attacked, becoming covered with a grayish white bloom, destroying the skin of the berries, and causing them to rot and dry up. This fearful disease spread itself speedily over other English grape hothouses; was observed almost simultaneously in like establishments at Paris, and passed thence over France, Italy, Greece, Tyrol and Hungary, affecting somewhat later and more feebly the vineyards on the Rhine. Rev. M. J. Berkeley, of Bristol, an eminent naturalist, who has devoted his life to the study of these minute organisms, was consulted, and diseased grapes submitted to his examination. He at once ascribed the cause of this injury to a new species of the botanical genus Oïdium, a vegetable fungus or parasite which, in honor of the horticulturist at Margate, he termed Oïdium Tuckeri. The genus Oïdium established by Link, belongs to the agamous plants, and is included in the Mucedineous family, (moulds.) It is described as a vegetable parasite preying upon living plants, like lice and other animal parasites upon animal species. At first this mould forms webby creeping filaments known in botanical language as Mycelium. These root-like fibres then branch out, sending up straight or decumbent articulated stems. These bead-like joints fill up successively with seeds or spores which are discharged at the proper time to multiply the species.

like

but

EFFECTS OF THE PARASITE UPON THE VINES.

The first effect is generally perceived upon the leaves, which, at their vernal growth in vineyards, turn whitish, owing to the development of mycelium, (see Plate I, Fig. 4a.) creeping first over the superior leaf-surface, constituting a feltmass, visible plainly under the microscope alone, then invading the whole leaf with rapidity. Sometimes the diseased leaves remain green and smooth, appear spotted. The spots differ much in appearance, and may be dirty brown and scarcely circumscribed or confluent; sometimes they are black, covering here and there the natural white down of the lower surface of the leaves, according to the variety of the vine. At other times the leaves crisp and curl up under the effect of the parasite, then fade and dry up, or turn black from the centre to the circumference, and, lastly, drop off, from the latter part of July to the beginning of August.

At this stage the vine is in a state of consumption-for the leaves are to plants what the lungs are to animals---and the functions of life are being suspended at the most important period of growth. The mycelium developing upon leaves produces relatively but few branches with seed capsules (spores,) whereas, when growing upon the berries of the grape, these are very numerous. When the shoots are attacked by the disease they are covered with spots of a variable diameter, or with large, irregular, often confluent blotches of a reddishbrown or even black color. (See Plate IV, Figs. 1 and 2.) Generally the spots preserve their primitive color, even after the August sap.

In the most affected vineyards the shoots look as if burned in different places, or as if a red-hot iron had been applied to their herbaceous surface. In several instances the same effect took place on the petioles (stems) of the leaves, and on the peduncles (stems) of the bunches of grapes. At times the shoots may be observed to secrete a clammy inodorous fluid all over their surface. The living parasite has also the power to penetrate into the young wood to the medullary canal, when the summit of the woody texture turns black and dry, and withers from the top down to half its length.

The symptoms presented by the affected grape are more variable. During

the first invasion of the oïdium, sometimes before, sometimes after its appearance on the leaves or shoots, a single whitish spot may be seen on a single berry, enlarging itself by radiating in irregular directions. The mycelium, with its fructifying stems, is limited or arrested, at times, in its growth, from some unknown cause; whilst, at others, it is seen spreading with great rapidity, covering the entire surface of the berries. If in a bunch there is but one abortive berry, it will bear marks of the disease. The creeping branches of the mycelium are fixed upon the skin of the berry by rootlets which do not penetrate into the juicy pulp. The mycelium sends up vertical fructiferous branches nearly of the same height, and densely pressed against each other, velvet-like. These branches are composed of, or subdivided into, transverse cells, (see Plate I, Figs. 1 and 6.) The top cell increases in volume, becomes ellipsoidal, and detaches itself at maturity, or is carried off by the slightest motion of the air. If the conditions (i. e., the temperature and dampness of the atmosphere) are favorable, a second and third cell will follow the same course, (see Plate I, Fig. 2.) These cells, called spores by botanists, correspond to the germs, buds or seeds of the higher orders of plants. The more or less elongated spores of the oïdium mould form capsules, consisting of two transparent integuments or skins. The spores are almost devoid of weight, and so small that their length only amounts to the 30 or 500 of a millimetre, or Toooo to Job of an inch, English measure. As soon as the deposited spore is favored by circumstances (i. e., a moist atmosphere and a temperature not less than 15° C. or 59° F.) it germinates. A sort of irregular bud (Plate III, Fig. 2, c) bursts forth at one of the ends or poles of the ellipsoid, elongating itself into creeping, webby fibres, which, at length, developing themselves into a net work of branches, form the mycelium. But the oïdium has yet another way of propagation, or revivifying as it were. If the mycelium is reduced to dry, inert, and almost imperceptible fragments, it constitutes, when placed under proper conditions of warmth and moisture, a true cutting, which soon sends forth two or three creeping rootlets, (see Plate III, Fig. 2, d.) These will produce vertical fruit branches, discharging successively the ripe sports, as has been already described.

3

The first effect observed of the mycelium, when adhering to the surface of the berries, consists in producing elevated, brown, (rarely red or black) points, unless they be certain varieties of grapes attacked toward maturity. Louis Leclerc, in his report to Monsieur le Ministre Persigny, remarks: "Certain learned physiologists, for whom I have perfect deference, entertain the opinion that these elevated points on the berries appear before the formation of the mycelium. Constant observations, extended for over three months, have failed to reveal to me a single example of such a phenomenon." Suppose this to be so, are these slight elevations the result of a developing internal sporule, or of the removal of the mycelium? Such apparently trifling facts are of great importance. The appearance of these elevated points before the oïdium proves that it is a pre-existing disease-a kind of eruption. These excrescences or round swellings (Plate III, Fig. 1, a) seem not to penetrate the pellicle, and consequently do not extend into the cellular tissue constituting the pulp of the berries. The excrescences, at first very indistinct, proceed, nevertheless, in irregular lines, according to the direction taken by the sterile base network of the mycelium. The elevated points are readily seen by the naked eye, by wiping off the oïdium with the finger, or when the latter is removed by some unknown cause, (Plate IV, Fig. 5.) These points are indelibly traced, whether they cover the whole berry, or are distributed in isolated patches; and it is always upon one of these punctuated lines, and longitudinally, that the pellicle of the berries opens. The berries themselves afterwards burst, owing to the weakness of the skin, or the great accumulation of the nutritive juice within. (Plate IV, Fig. 5.) The cellular tissue forming the pulp is next torn, leaving the seeds naked.