Red corpuscles, per c. mm. 3,692,000 = 73·8 per cent. Hæmoglobin 80 ” Colour index 1·08 ” Leucocytes, per c. mm. 25,920 DIFFERENTIAL COUNT. Lymphocytes 8·0 per cent. = 2,074 per c. mm. Large mononuclears 3·5 ” = 907 ” Polymorphonuclears 87·0 ” = 22,550 ” Eosinophiles 0·5 ” = 130 ” Mast cells 1·0 ” = 260 ” ----- 100·0 The salient feature of the blood picture is the high grade _leucocytosis_ of leucoid type with moderate anæmia—appearances quite compatible with, and suggestive of, an _infective_ arthritis. To these interesting blood changes we shall again refer when dealing with the acute polyarticular variety, the above case being of monarticular type, _i.e._, the big toe. _Uric Acid Excretion._—If when on a _purin-free_ diet a gouty subject develops a paroxysm, the curve of uric acid excretion in the urine is so characteristic as to be almost pathognomonic of the disorder. As His pointed out, immediately before the onset of the paroxysm the endogenous uric acid sinks to a lower level (termed by Umber the _anacritical stage of depression_). With the onset of the attack the uric acid content of the urine quickly increases, to reach its zenith on the second or third day. F. Pfeiffer, who first noted this point, termed it an _uric acid wave_. Subsequently, with the gradual subsidence of the paroxysm, it again drops into what Umber termed the _post-critical stage of depression_. While this curve of endogenous purin excretion may be modified by oft recurring exacerbations, still Umber holds that nevertheless it is of decided value in differential diagnosis. _Local Phenomena._—The site and character of the pain having been dealt with, we now pass on to consider the objective changes in the affected part. The local _engorgement_ of veins that _precedes_ the _articular_ outbreak becomes more pronounced, extending from the vicinity of the painful joint as far as the leg. The overlying skin of the joint quickly becomes red and tumid. It is not a bright, but a dark red, the superjacent skin taking on a shining smoothness that has been compared to the peel of an onion. Indeed, in its more violent form it resembles but too closely the ordinary appearance of an _abscess_, over which the skin is becoming thin. The redness is not strictly confined to the surface of the joint, but spreads a little beyond, and where it ceases _œdema_ is perceptible.