The length of its valley (excluding the lesser windings of the river) is about 90 m., and the drainage area about 1300 sq. m. It is navigable only for a few miles above the mouth, but its salmon fisheries are both attractive to sportsmen and of considerable commercial value. The scenery of its banks is at many points very beautiful.
BLACKWATER FEVER, a disease occurring in tropical countries and elsewhere, which is often classed with malaria (q.v.). It is characterized by irregular febrile paroxysms, accompanied by rigors, bilious vomiting, jaundice and haemoglobinuria (Sambon). It has a wide geographical distribution, including tropical Africa, parts of Asia, the West Indies, the southern United States, and—in Europe—Greece, Sicily and Sardinia; but its range is not coextensive with malaria. Malarial parasites have occasionally been found in the blood. Some authorities believe it to be caused by the excessive use of quinine, taken to combat malaria. This theory has had the support of Koch, but it is not generally accepted. If it were correct, one would expect blackwater fever to be regularly prevalent in malarial countries and to be more or less coextensive with the use of quinine, which is not at all the case. It often resembles yellow fever, but the characteristic black vomit of yellow fever rarely occurs in blackwater fever, while the black urine from which the latter derives its name is equally rare in the former. According to the modern school of tropical parasitology, blackwater fever is neither a form of malaria nor produced by quinine, but a specific disease due to a protozoal parasite akin to that which causes the redwater fever of cattle.
BLACKWELL, THOMAS (1701–1757), Scottish classical scholar, was born at Aberdeen on the 4th of August 1701. He took the degree of M.A. at the Marischal College in 1718. He was appointed professor of Greek in 1723, and was principal of the institution from 1748 until his death on the 8th of March 1757. In 1735 his first work, An Inquiry into the Life and Writings of Homer, was published anonymously. It was reprinted in 1736, and followed (in 1747) by Proofs of the Enquiry into Homer’s Life and Writings, a translation of the copious notes in foreign languages which had previously appeared. This work, intended to explain the causes of the superiority of Homer to all the poets who preceded or followed him, shows considerable research, and contains many curious and interesting details; but its want of method made Bentley say that, when he had gone through half of it, he had forgotten the beginning, and, when he had finished the reading of it, he had forgotten the whole. Blackwell’s next work (also published anonymously in 1748) was Letters Concerning Mythology. In 1752 he took the degree of doctor of laws, and in the following year published the first volume of Memoirs of the Court of Augustus; the second volume appeared in 1755, the third in 1764 (prepared for the press, after Blackwell’s death, by John Mills). This work shows considerable originality and erudition, but is even more unmethodical than his earlier writings and full of unnecessary digressions. Blackwell has been called the restorer of Greek literature in the north of Scotland; but his good qualities were somewhat spoiled by pomposity and affectation, which exposed him to ridicule.
BLACKWOOD, WILLIAM (1776–1834), Scottish publisher, founder of the firm of William Blackwood & Sons, was born of humble parents at Edinburgh on the 20th of November 1776. At the age of fourteen he was apprenticed to a firm of booksellers in Edinburgh, and he followed his calling also in Glasgow and London for several years. Returning to Edinburgh in 1804, he opened a shop in South Bridge Street for the sale of old, rare and curious books. He undertook the Scottish agency for John Murray and other London publishers, and gradually drifted into publishing on his own account, removing in 1816 to Princes Street. On the 1st of April 1817 was issued the first number of the Edinburgh Monthly Magazine, which on its seventh number, bore the name of Blackwood’s as the leading part of the title. “Maga,” as this magazine soon came to be called, was the organ of the Scottish Tory party, and round it gathered a host of able writers. William Blackwood died on the 16th of September 1834, and was succeeded by his two sons, Alexander and Robert, who added a London branch to the firm. In 1845 Alexander Blackwood died, and shortly afterwards Robert.
A younger brother, John Blackwood (1818–1879), succeeded to the business; four years later he was joined by Major William Blackwood, who continued in the firm until his death in 1861. In 1862 the major’s elder son, William Blackwood (b. 1836), was taken into partnership. John Blackwood was a man of strong personality and great business discernment; it was in the pages of his magazine that George Eliot’s first stories, Scenes of Clerical Life, appeared. He also inaugurated the “Ancient Classics for English readers” series. On his death Mr William Blackwood was left in sole control of the business. With him were associated his nephews, George William and J. H. Blackwood, sons of Major George Blackwood, who was killed at Maiwand in 1880.
See Annals of a Publishing House; William Blackwood and his Sons . . . (1897–1898), the first two volumes of which were written by Mrs Oliphant; the third, dealing with John Blackwood, by his daughter, Mrs Gerald Porter.
BLADDER (from A.S. blaēddre, connected with blāwan, to blow, cf. Ger. blase), the membranous sac in animals which receives the urine secreted from the kidneys. The word is also used for any similar sac, such as the gall-bladder, the swim-bladder in fishes, or the small vesicle in various seaweeds.
BLADDER AND PROSTATE DISEASES. The urinary bladder in man (for the anatomy see Urinary System), being the temporary reservoir of the renal secretion, and, as such, containing the urine for longer or shorter periods, is liable to various important affections. These are dealt with in the first part of this article. The diseases of the prostate are so intimately allied that they are best considered, as in the subsequent section, as part of the same subject.
Diseases of the Bladder.
Cystitis, or inflammation of the bladder, which may be acute or chronic, is due to the invasion of the mucous lining by micro-organisms, which gain access either from the urethra, the kidneys or the blood-stream. It is easy to see how the diplococci of gonorrhoea may infect the bladder-membrane by direct extension of the inflammation, and how the bacilli which Cystitis. are swarming in the neighbouring bowel may find access to the urethra or bladder when the intervening tissues have been rendered penetrable by a wound or by inflammation. Sometimes, however, especially in the female, the germs from the large intestine enter the bladder by way of the vulva and the urethra.
Any condition leading to disturbance of the function of the bladder, such as enlargement of the prostate, stricture of the urethra, stone, or injury, may cause cystitis by preparing the way for bacillary invasion. The bacilli of tuberculosis and of typhoid fever may set up cystitis by coming down into the bladder from the kidneys with the urine, or they reach it by the blood-stream, or invade it by the urethra. Another way of cystitis being set up is by the introduction of the germs of suppuration by a catheter or bougie sweeping them in from the urethra; or the instrument itself may be unsterilized and dirty and so may introduce them. It used formerly to be thought that wet or cold was enough to cause inflammation of the bladder, but the probability is that this acts only by lowering the resistance of the lining membrane of the bladder, and preparing it for the invasion of the germs which were merely waiting for an opportunity. In the same way, gout or injury may lead to the lurking bacilli being enabled to effect their attack. But in every case disease-germs are the cause of the trouble, and they may be found in the urine. The first effect of inflammation is to render the bladder irritable, so that as soon as a few drops of urine have collected, the individual has intense or uncontrollable desire to micturate. The effort may be very painful and may be accompanied by bleeding from the overloaded blood-vessels of the inflamed membrane. In addition to blood, pus is likely to be found in the urine, which by this time is alkaline and ammoniacal, and teeming with micro-organisms. As regards treatment, the patient should be at once sent to bed in a warm room, and should