The patch of eruption is made up of several concentric rings. Difference of duration of the individual rings, usually slight, tends to give the patch variegated coloration; as, for example, in erythema iris and herpes iris. #What meaning is conveyed by the term "marginate"?# The sheet of eruption is sharply defined against the healthy skin; as, for example, in erythema marginatum, eczema marginatum. #What meaning is conveyed by the qualifying term "circumscribed"?# The term is applied to small, usually more or less rounded, patches, when sharply defined; as, for example, the typical patches of psoriasis. #When is the qualifying term "gyrate" employed?# When the patches arrange themselves in an irregular winding or festoon-like manner; as, for instance, in some cases of psoriasis. It results, usually, from the coalescence of several rings, the eruption disappearing at the points of contact. #When is an eruption said to be serpiginous?# When the eruption spreads at the border, clearing up at the older part; as, for instance, in the serpiginous syphiloderm. #RELATIVE FREQUENCY.# #Name the more common cutaneous diseases and state approximately their frequency.# Eczema, 30.4%; syphilis cutanea, 11.2%; acne, 7.3%; pediculosis, 4%; psoriasis, 3.3%; ringworm, 3.2%; dermatitis, 2.6%; scabies, 2.6%; urticaria, 2.5%; pruritus, 2.1%; seborrh[oe]a, 2.1%; herpes simplex, 1.7%; favus, 1.7%; impetigo, 1.4%; herpes zoster, 1.2%; verruca, 1.1%; tinea versicolor, 1%. Total: eighteen diseases, representing 81 per cent. of all cases met with. (These percentages are based upon statistics, public and private, of the American Dermatological Association, covering a period of ten years. In private practice the proportion of cases of pediculosis, scabies, favus, and impetigo is much smaller, while acne, acne rosacea, seborrh[oe]a, epithelioma, and lupus are relatively more frequent.) #CONTAGIOUSNESS.# #Name the more actively contagious skin diseases.# Impetigo contagiosa, ringworm, favus, scabies and pediculosis; excluding the exanthemata, erysipelas, syphilis and certain rare and doubtful diseases. [At the present time when most diseases are presumed to be due to bacteria or parasites the belief in contagiousness, under certain conditions, has considerably broadened.] #RAPIDITY OF CURE.# #Is the rapid cure of a skin disease fraught with any danger to the patient?# No. It was formerly so considered, especially by the public and general profession, and the impression still holds to some extent, but it is not in accord with dermatological experience. #OINTMENT BASES.# #Name the several fats in common use for ointment bases.# Lard, petrolatum (or cosmoline or vaseline), cold cream and lanolin. #State the relative advantages of these several bases.#