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Hydrocephalus, or water in the head, in one of its forms, is a tuberculous inflammation of the internal serous membranes of the brain. It is ushered in by languor, disordered digestion, irregularity of the bowels, and a falling off in condition. The limbs become weak and tottering; the head is hot and tender, and held in a dependent position; the eyes are impatient of light, and the pupils partially closed; there is more or less fever and an accelerated pulse. These symptoms, indicative of active inflammation, give way, after a variable time, to others significant of effusion and pressure on the brain. All the external perceptions become blunted, and the pulse is slow. As the fluid accumulates, the head enlarges, and the bones become soft and thin. This state of depression usually continues until death. The disease is one of early life; it is rarely met with in animals of more than six months or a year old. As has been already remarked, it is sometimes congenital, and, in such cases, there is usually a great increase in the size of the head, from the amount of the effusion and the soft, yielding nature of the cranial bones. The substance of the brain is found, on examination, to be expanded by the contained fluid, and soft and infiltrated with a thin serosity. The membranes of the brain are much inflamed, coated with lymph, and studded with granules and tubercles, which are also found in other parts of the body, especially in the mesenteric glands, and are in all respects identical with those found in the lungs of consumptive patients. These facts establish the scrofulous nature of the disease, and its close connexion with consumption.

Tabes Mesenterica is more common in foals than is generally supposed: it occurs at various ages, but seldom affects animals more than two years old. The matter of tubercle is deposited in the mesenteric glands; and this, interfering with their functions and preventing the due elaboration of the chyle, speedily causes derangement of digestion, imperfect assimilation, and consequently rapid wasting and death from inanition. Apparent recoveries occasionally take place, the tubercular matter becoming cheesy, hard, and gritty; but as the lungs also are usually diseased, recovery is often only temporary, and the animal by and by dies either of phthisis pulmonalis, or of glanders.

We have noticed that variety of consumption affecting the limbs, or rickets; that variety affecting the contents of the cranial cavity, or hydrocephalus; that variety affecting the abdominal cavity, or tabes mesenterica; and have now to notice that variety, perhaps, of all the most common and fatal, and which has its seat in the lungs; this is pulmonary consumption, or phthisis pulmonalis. It consists in a deposition of tubercular

matter in the lungs ; at first soft and cheesy, or gluey and fibrinous, and becoming, after a time, hard and gritty, but always unorganisable. Its symptoms are irritation of the mucous lining of the bronchia and lungs, as evidenced by cough; occasional febrile symptoms, wasting, and debility, which, in bad cases, sets in early, and is so excessive as speedily to destroy life. We have treated very briefly of tabes mesenterica and of consumption in horses, because we shall have to return to them when speaking of the hereditary diseases of cattle, in which they are more common than in the horse.

These are the most common forms in which a scrofulous diathesis shows itself, but there are other irregular forms which it also sometimes assumes. In early life especially, we recognise it in intractable swellings of the joints, from unhealthy inflammation of their synovial fringes, and in accumulations of pus in various parts of the body. These two forms are often met with in different individuals of the same stock, and are always notoriously hereditary. I know at present of two entire horses, both of fine symmetry and apparently sound and vigorous health and constitution, that have for several seasons got stock, many of which have died within a short time after birth from these complaints, and others have long continued sick and ailing. A pony, in sound health, and which had previously reared a strong and vigorous foal, got by another sire, had a foal to one of these horses. From birth it was weak on its legs, and died before it was three weeks old: an immense accumulation of pus was found underneath the psoae muscles, and all the larger joints were inflamed, especially the stifle joints. In the succeeding year the same pony had another foal to the same horse, which again showed similar symptoms, and died about the same time after birth. Again, in the next year the pony was put to another horse, and had a foal which remained perfectly free from disease. This case, we think, distinctly proves the transmission by the sire of a scrofulous diathesis. The disease of the foals could not depend upon accidental circumstances, for a similar affection occurred in many of the stock got for several seasons by the same horse. The disease was in this instance ascribable to the sire, and not to the dam,-which is obvious from the fact, that the same mare produced and reared a healthy foal both before and after she had the two diseased ones. This last observation must not, however, be misconstrued, as leading to the belief that diseases are inherited from the male alone; on the contrary, form, disposition, and tendency to disease, all depend quite as often on the mother as on the sire.

But a scrofulous diathesis, besides appearing in the forms

above noticed, also constitutes a powerful predisposition to many diseases. In scrofulous subjects sore shins often occur―a complaint common in many racing studs, appearing chiefly in young and rapidly-growing animals, depending on the excessive exertions to which they are subjected in training, consisting of inflammation of the periosteum investing the cannon bones, especially of the hind limbs, and, when neglected, often running on to caries and necrosis..

*

From their weak and unsound constitution, horses of a scrofulous diathesis are unusally prone to glanders and farcy-two forms of a disease peculiar (at least as an original disease) to the equine species. As has been already remarked, it is characterised by a specific unhealthy inflammation, identical in all important characters with the syphilitic inflammation in man. From the dire and loathsome nature of glanders, and the terror in which it is held, animals affected by it are never used for breeding, so that we have little opportunity of judging of its hereditary nature. There is no evidence (so far as I know) which proves it to be directly hereditary, but there is no doubt that the progeny of a glanderous horse would exhibit an unusually strong tendency to the disease. Its ordinary predisposing causes are, many of them, hereditary: it is very prone to attack animals of a weak or vitiated constitution. It is emphatically the disease which cuts off all horses that have had their vital energies reduced below the healthy standard, either by inherent or acquired causes. Glanders is also sometimes caused by inoculation; is frequently produced in healthy subjects by mismanagement, as by insufficient food, want of shelter, and overwork; and often supervenes on bad attacks of influenza, strangles, diabetes, and other diseases which debilitate the system, or impair the integrity of any of its more important parts. These causes appear to possess the power of engendering in the constitution of the horse a peculiar poison, which, as it reproduces itself, and spreads to all parts of the body, gives rise to the characteristic symptoms of glanders, causing, sooner or later, a breaking up of the system, and a fatal prostration of the vital powers. This poison produces in the blood abnormal changes, which vitiate that fluid, and unfit it for healthy nutrition. From the irritant action of the morbid fluids passing through them, the lymphatic glands and

* Though I am not aware of any facts proving glanders to be congenital, yet I think there is every probability that such is the case; for it is notorious that syphilis, the analogous disease in the human subject, is congenital, and often appears at birth in the children of women affected by that disease.

A comparison of the two subjoined analyses will show the great difference in composition between the blood of healthy and of glanderous horses-a difference

vessels become inflamed, and lymph is deposited. This, however, being of an unhealthy nature, soon runs on to softening, which extends to the skin overlying the part, and ulcerating farcy-buds are formed. On the surface of the more vascular mucous membranes effusions of tubercular matter are also poured out; these take on an unhealthy inflammation, and degenerate into chancrous ulcers, which may generally be seen on the mucous membrane of the nostrils in most bad cases of glanders.

These are the most common scrofulous diseases of horses; but an animal of the scrofulous diathesis, besides being specially subject to these, is little able to withstand ordinary morbific causes, and hence is also unusually liable to many ordinary diseases; in such a subject, too, disease is very apt to be severe and complicated, and to be acted on tardily and imperfectly by all remedies.

[Papers by the same author, on the hereditary diseases of cattle and pigs, will appear in future numbers of the Journal.]

IX.-Report upon the Rye and Derwent Drainage.
By JOHN HENDERSON.

To Mr. Pusey.

SIR,-It affords me great pleasure to comply with your request to furnish the readers of the Society's Journal with a report upon the proceedings of the Commissioners of the Rye and Derwent Drainage.

Natural causes during the present unusually wet season seem to give additional weight to the deductions of scientific agriculture, in urging the attention of the public to the subject of District Drainage, at a time when our valleys are converted into lakes, our drains choked up, and the land so injuriously saturated with moisture that it is impossible to exaggerate the importance of the subject, or calculate the enormous damage which has been done by a few weeks of very rainy weather.

It is admitted by all that the first principle of agriculture is the thorough drainage of the land, and the first requisite of

consisting chiefly in a diminution of the red corpuscules, and a proportional increase of the fibrine and albumen :

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Simon's Animal Chemistry, by Dr. Day, vol. i. pp. 346-7.

VOL. XIV.

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thorough drainage a sufficient outfall. The farmer may design deep drainage the sanitary reformer attempt to remove miasmata-the machine may pour out its countless pipes and tilesand national loans may contribute to putting them into the ground, but all is of little use unless you previously procure a sufficient outfall.

The rivers, and their tributary streams, are the natural drainage of a country, and it is to the condition and improvement of these, -the great arteries of drainage, that I am anxious to draw public attention, even in districts where it is supposed, at first sight, that no improvement in outfall is required. In fenny districts, the difficulty of drainage has long since stimulated the attention of the owners of land in these districts, and art has accomplished with much success what nature, in the greater number of valley formations, will herself perform if unfettered by those artificial obstructions which the necessities of former times, and varied circumstances, have interposed. Generally speaking a river or stream will preserve for itself, if left intact, a sufficient fall for the discharge of its waters, and carry on an efficient drainage of a district or valley, just in proportion to the tenacity of the soil and the elevation of the basin of the valley above the high-tide level of the sea. But, unfortunately, in long settled and densely populated countries like "Old England," there are few rivers, or even streams, that retain at this day their natural features, but, either for the sake of water-power for mills, or headwater for navigation, they have been dammed up above their primitive levels, and the natural drainage of the district interrupted or entirely destroyed.

When our Saxon forefathers founded our villages, and the feudal mill rose upon the banks of our rivers, the plough required but little scope for its industry, and the flat and fertile water valleys were depastured by their cattle, the forest supplied the fuel of their hearth, and the domestic quern or the rude watermill prepared their grain,-the want of roads localized their wants and limited their sympathies. But the spirit of the nineteenth century has other requirements. A redundant population cannot spare one acre of land suitable for human industry, and "unrestricted competition" cannot afford to neglect the combined advantages of nature and art;-the earth yields her "black diamonds" alike for the furnace and the domestic fire, and steam and the rail, with impartial energy, distribute them far and wide; the rude mill has given place to wonderful and infinitely applicable machinery, and water-power is well nigh superseded by that of steam. It is time, therefore, that the landed proprietor and the farmer should turn their attention to the condition of their rivers and streams, with the view of restoring to them their natural

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