_Changes in the Blood._—The findings are extremely interesting in view of the high grades of _leucocytosis_ to be met with both in _pyrexial_ and _apyrexial_ examples. In a case of _acute gouty polyarthritis_ under my care the blood picture was a very striking one. The patient had suffered from gout for some eleven years, with recurrent acute exacerbations. There was widespread involvement of the joints both in upper and lower limbs. On the dorsum of the mid-phalangeal joints small semi-solid swellings were present, the exact nature of which was somewhat puzzling. But inasmuch as the pinna in both ears was studded with _tophi_, this seemed to provide a clue. The auricular tophi were verified microscopically. The extra-articular phalangeal swellings were then aspirated with a hypodermic syringe. A turbid straw-coloured fluid issued, which microscopically was found to contain _biurate_ crystals. His temperature rose nightly from 101° up to 102° F., with morning remissions. The left knee and wrist were the seat of _effusion_, and some of the small finger joints were inflamed. BLOOD COUNT. Red corpuscles, per c. mm. 4,432,000 = 88·6 per cent. Hæmoglobin 60 ” Colour index ·68 ” Leucocytes, per c. mm. 27,200 DIFFERENTIAL COUNT. Lymphocytes 9 = 2,450 Large mononuclears 13 = 3,540 Polymorphonuclears 78 = 21,220 Eosinophiles 0 = 0 Mast cells 0 = 0 ----- 100·0 The left knee joint was aspirated by Dr. Munro. A clear fluid of straw yellow tint was withdrawn, which yielded some fibrin on standing. The cytological examination gave the following results:— TOTAL COUNT. 44,800 per c. mm. (nearly all leucocytes). DIFFERENTIAL COUNT. Polymorphonuclears 92 Lymphocytes 7 Large mononuclears 1 Eosinophiles 0 Basophiles 0 --- 100 Attempts at culture on broth and agar proved _sterile_. In addition three separate blood cultures, taken at intervals of a few days, on agar slopes and broth, all gave _negative_ results. In another instance of _polyarticular_ distribution the subject was seen during the _inter-paroxysmal_ period. He displayed auricular _tophi_, the crystalline content of which was verified microscopically. BLOOD COUNT. Red corpuscles, per c. mm. 5,732,000 = 194·6 per cent. Hæmoglobin 65 ” Colour index ·57 ” Leucocytes, per c. mm. 13,200