Diagnosis.— The chancre or indurated ulcer which appears upon that portion of the body where inoculation has taken place, which may be at any point where the skin or mucous membrane has been broken or injured, has been regarded since the time of John Hunter as the distinguishing evidence that syphilis is present. The discharge or secretion from such a sore, as well as the blood of the individual who has the sore, both of which contain the germs of the disease are the media by which the disease is communicated, while the period during which such communication is possible may continue through several years if the disease remains untreated. These germs produce a specific antigen, by their action upon the blood and tissues, and this forms the basis for the Was sermann test in the diagnosis of syphilis. This test works upon the theory of deviation of the complement by antigen substances contained in the syphilitic fluid blood or cerebrospinal fluid and prevents or fails to prevent the lytic action of the hmnolysing fluid, according as syphilis is present or absent.
The Wassermann test is made in the follow ing manner. Certain definite quantities of tis sue, representing the antigen, are taken from the liver and spleen of a syphilitic fcetus, to gether with a definite volume of the blood serum of the individual upon whom the test is to be made. They are mixed in a test tube and fresh normal guinea-pig serum which con tains the complement is added to them. The tube is then placed in an incubator, at the temperature of the body. for one hour, after which its contents are poured into a second test tube which contains• a mixture of red blood cells of a sheep, or other suitable animal, sus pended in a physiological salt solution plus the serum of a rabbit which has been immunized to the before-mentioned red blood cells of the sheep. If the individual whose serum was placed in the first test tube actually has syphilis there will be no haernolysis of the red blood cells in the second tube after it has been kept in the incubator for the required period of one hour. In other words there is fixation of the complement and the reaction is said to be posi tive. If, on the other hand, hsemolysis of the red blood cells takes place the reaction is negative and the individual presumably does not have syphilis, or has it in a quiescent con dition. Various errors may occur with the Wassermann test, so that it is not regarded as absolutely reliable. This has resulted in the development of various modifications of the test, the one which has been regarded as most satisfactory being known as the Nogucht nodi fication. The Wassermann test or the Noguchi modification must be repeated at intervals of a month or two for a year or more, even though it should be negative on each occasion, to de termine whether the disease has been entirely eradicated.
Mercury and the iodide of potassium have until a very recent date formed the basis of most of the successful treatment of syphilis. A great deal of enthusiasm was ex cited by the first published results of the use of salvarsan or results which unfor tunately have not been confirmed by a more extended experience. While there is no ques tion of the incontestable efficacy of this remedy in causing the earlier lesions of syphilis to disappear, and even certain intractable lesions of a later stage, yet relapses are the rule and even more common, it would appear, than after the use of mercury. The effect of a remedy in preventing the dreaded manifestations of the disease upon the nervous system and the organs essential to life is the crucial test of its cura tive value. It will be necessary to wait several years before we can estimate its curative effi ciency as determined by the ulterior evolution of the disease. There is reason to doubt whether any chronic infectious disease like tuberculosis, leprosy and syphilis can ever be expelled by therapeutic violence. The most refractory and difficult form of syphilis to treat is neurosyphilis, or syphilis of the nervous sys tem. Neurosyphilis may give rise to a great variety of different types of disease, so great that the general practitioner can hardly bear them all in mind. Special methods of treat ment are essential in these forms of syphilis. Consult Jelliffe and White, of the Nervous System> (3d ed., 1919).
SYR, or SIR DARYA, ser-dieya, Tur kestan, (1) A river (the ancient Jaxartes) rising in the Thian-Shan Mountains on the boundary of East Turkestan and flowing west and northwest into the Aral Sea. It traverse, the districts of Ferghana, Samarkand and Darya and has a total length of about I no miles. In its upper course it receives numert-..te.
tributaries. After leaving the mountain regions in a series of rapids it flows for the rest of its course over the vast arid plains of the Syr Darya district, where it is broad, deep and tranquil, but receives few affluents. It here repeatedly divides itself and numerous irriga tion canals lead from it into the surrounding country. The river is navigable for 600 miles, but the proposed line of steamers has not yet been installed. (2) A district of Turkestan with an area of 194,853 square miles. The capital is Tashkend; pop. about 150,000. The population of the district is 1,990,000.