This may be immediate or secondary, that is, occurring after an interval varying from two or three days to a week. When occurring later than this it may be regarded as due either to a repetition of injury, or to some constitutional cause - for example, syphilis, rheumatism, gout, septicaemia, etc.

Tension is always associated with local heat, although in some cases this is very slight; the more quickly a high degree of tension follows the injury the greater is the heat; the same may be said of the pain, which, in immediate tension, is sometimes of great intensity. Hence it is the pain from which relief is sought. Rest, of course, is essential, and if this, aided by very hot fomentation, fails to give comfort, direct relief by means of the aspirator is the indication. This in the hands of a competent practitioner who understands the value of cleanliness is not only more effectual than the alternative usually recommended, namely, leeches, but is also, I think, safer. I have seen no harm follow aspiration, which I cannot say in the case of leeches. The withdrawal of only a sufficient amount of the bloody fluid to relieve the tension should be made, as this is less likely to be followed by a recurrence than when as much fluid as possible has been drawn off. The tendency to recurrent tension in cases of this kind is also, I have reason to believe, diminished by the administration internally of calcium chloride. In the case of tension coming on after an interval, on the other hand, if relief by aspiration becomes necessary, as much fluid (synovia) should be removed as possible, and firm pressure immediately applied. After the relief of tension, the use of massage and movement, voluntary and passive, will be regulated entirely by the behaviour of the local temperature of the part, to which reference has already been made.