Excellent heat effects are produced by Diathermy where by employing currents 40o to Soo milliamperes from Simon's apparatus and the Poulsen lamp the interior of the joint can be submitted to great heat for 15 or 20 minutes at a time; this method of employing heat is also known as " Thermo-penetration," and differs from other methods of using heat.
Moist heat in the form of poultices, fomentations, vapour, Russian and hot-water baths is decidedly inferior to dry heat. Perhaps the best form for the general or local employment of moist heat is the mud-bath.
The previous statement made about the value of electricity applies almost equally to the use of dry and moist heat; these agents are of little use unless when followed by passive movements and massage. The local application of dry heat often renders joint motion possible where pre viously stiffness and apparent ankylosis had rendered the articulation fixed, but a speedy relapse to the rigid condition is the invariable rule in these cases unless when perseveringly followed up by exercises and thorough local massage.
Hydrotherapy and Spa obviously this includes the application of moist heat, it may be referred to at further length. The list of spas where thermal and medicated waters are employed both externally and internally is almost interminable. At home, Bath, Buxton, Strathpeffer, Harrogate, Woodhall, Llandrindod Wells, and Llangammarch are favourite resorts, and at Matlock Bath every arrangement for the treatment of the disease is carried out upon pure hydropathic and thermo therapeutic lines. Of these, Bath is decidedly the most valuable on account of the high temperature of its saline springs and the mildness of its winter, and every hydropathic, electric and massage requirement can be obtained there as well as at Buxton,Il arrogate and the other spas. The brine baths of Droitwich and Nantwich, though more suitable for chronic rheumatism or fibrositis, are also sometimes useful, but often they aggravate at least during the time of their employment. The thermal springs abroad are very popular—Baden-Baden, Aix-la-Chapelle, Wiesbaden, Carlsbad, Dax, Wilbad, Vichy, Aix-les-Bains, etc. Many other resorts devoid of thermal springs are also in favour, as Baden, Franzensbad, Pyrmont, etc.
The advantages derivable from a course of treatment at any of these places are due mainly to the bathing, massage, douchage, etc., though the value of the alkaline and sulphurous waters internally cannot be entirely overlooked, since metabolism and elimination become markedly increased under their use, but it must be remembered in the spa treatment of rheumatoid arthritis that lowering or depressing agents should always be avoided, and acute cases cannot be sent away.
The douching—horizontal jet, percussion, needle and filiform douches – should be combined with massage. The Scotch douche, which consists in the application of the horizontal douche with cold and hot water alter nately, is much employed. The Aix douche is the most valuable form of hydropathic treatment; it is also known as the " massage douche," in which massage is employed under a warm douche whilst the spine is acted upon by a continuous-needle spray, the seance being completed by a warm needle spray bath which is gradually cooled to the temperature of the air. A modification of Aix douche is practised at Vichy, which starts with a steam or hot vapour bath preliminary to the massage.
Electricity, passive and active movements, radiant heat, luminous thermo-electric and Greville baths and the electric-light bath, in which the body is exposed to the light from arc lamps, with but slight elevation of temperature, may all be employed in conjunction with hydropathy and massage or mechanical vibration.
Cataphoresis.—This treatment of late years has been followed by excellent results especially in the mono-arthritic type of the disease. The joint in Somerville's method is surrounded with many layers of lint saturated with a weak solution of Salicylate, Iodide or Chloride of Sodium; over this is bound a layer of metal gauze connected with the negative pole of a galvanic battery, whilst the positive electrode is placed over a large pad of lint soaked in salt solution applied to any indifferent region of the body. When the current is turned on, the salicylic, iodine or chlorine ion is driven in through the skin. The operation can be con ducted to best advantage after the application of radiant heat.