Psychoanalysis

Diseases of Function.—Functional disorder and the investi gation of the early stages of disease, before the physical signs of gross structural changes appear, have attracted increasing atten tion and are intimately wrapped up with the prevention of disease. The first manifestation of disease is commonly disorder of func tion, which shows itself by symptoms unaccompanied by any structural change. Clinical observation was specially directed to the detection of the earliest signs of disease by the late Sir James Mackenzie, who in 1919 started team work in this direction at the St. Andrews Institute for Clinical Research, where laboratory tests were fully utilised as an aid to the careful analysis of the patient's symptoms in an intense search for a real understanding of the familiar manifestations of undue fatigue, malaise, shortness of breath on exertion and pain. Tests for disorder of function— some physical, as in disorders of the circulatory and respiratory organs, others chemical, such as examination of the blood and the ability of the organ to excrete coloured dyes, for example, phenol-sulphone-phthalein, as in disease of the kidney and the liver, others psychological, as in nervous disorder—have recently been much elaborated and multiplied, and bid fair to facilitate more accurate and early diagnosis and treatment on scientific lines.

Psychology (q.v.).

Experimental psychology, once regarded as an academic pursuit, has been the means of great economic saving in industry, and the results of research work and tests have led to the introduction of rest pauses and other modifica tions, with the result of an increased output of work on the one hand and benefit to the worker on the other. The Industrial Fa tigue Research Board was set up during the war, and The National Institute of Industrial Psychology, established in Great Britain after the war, ensures continued practical guidance for employers and employed. (See INDUSTRIAL PSYCHOLOGY.) Endocrinology (q.v.). Ductless Glands.—The part played by the ductless or endocrine glands in the production of disease has attracted increasing discussion, especially on the questions (I ) of the endocrine balance, meaning thereby that when one gland is disordered the equilibrium which normally exists between them as a whole is upset, and (2) of the effects of disease of more than one of these glands—pluriglandular disorder. This last problem has on the one hand, from the difficulty of positive proof, aroused scepticism as to its existence, and on the other hand stimulated exploitation of commercial preparations of combined glandular extracts, the activity of which, as regards some of the constituents, is open to serious doubt. The outstanding advance in the medic inal use of endocrine preparations, and indeed in therapeutics generally, is the introduction of insulin (q.v.) for the treatment

of diabetes mellitus (q.v.). (See THERAPEUTICS.) The use of the endocrine preparations proved to be active is passing out of the qualitative stage into the further one in which they are being so standardised that the proper dose can be ad ministered ; this has been done for insulin, adrenalin, thyroid and parathyroid extracts. The interstitial cells of the testis ("inter stitial gland") have attracted much research in connection with their influence on the secondary sex characters and in insanity. Ex perimental ligature of the duct of the testis (vasectomy) increases the prominence of the interstitial gland and is followed by re juvenation (Steinach), and with this object the operation has been often performed on men, as has grafting of testes of men or chimpanzees (Voronoff). (See REJUVENATION.) Cardiology and Circulatory Organs.—The work of the late Sir James Mackenzie and Sir Thomas Lewis has so revolutionised our knowledge of the heart that there is a new cardiology (see HEART, DISEASES or). By the electrocardiograph, which is spe cially valuable in showing the condition of the heart muscle, Lewis showed that the extreme irregularity of the heart in cardiac failure, called by Mackenzie nodal rhythm, is due to auricular fibrillation, a circus movement instead of the normal contraction; it is in this condition that digitalis is of value. By means of the graphic methods the irregularities of the heart have been classified.

Angina Pectoris.—Cardiac murmurs have been shown not necessarily to be of grave importance, and much work has been done on angina pectoris. The symptoms—status anginosa—of sudden obstruction of the coronary arteries which supply the heart have been defined, and the cause of angina pectoris has been re ferred to the failure of the heart muscle (Mackenzie), and to disease of the first part of the aorta (Allbutt) ; in accordance with the last view operative division or removal of its nerves has been practised and found to relieve the pain, but not otherwise to affect the disease. Bullets embedded in the heart-wall have been removed, and a contracted (mitral) valve has been remedied by surgical measures. (See HEART AND LUNG SURGERY.) Blood-pressure.—The existence of high blood-pressure without kidney disease or hyperpiesia (Allbutt) has been established, and it has been suggested that table salt and, probably with more reason, guanidine raise, and that hepatic extract lowers blood pressure. The state of the capillaries—microscopic vessels—their power to contract, and their influence on blood-pressure have been investigated and much new knowledge has been acquired. The prevention of rheumatic heart disease and the responsibility of tonsils and other sites of focal infection have received consid erable attention both in Great Britain and in America.