A positive reaction in children under two years of age signifies, generally, active tuberculous process; with the advance of age the determination of active tuberculous processes by means of cutaneous tuberculin test becomes impossible. III. CONJUNCTIVAL TUBERCULIN TEST 1. SYNONYMS: Eye Test; Ophthalmic Test; Wolff-Eisner's Test; Calmette's Test. 2. APPARATUS AND DILUTIONS NECESSARY: 1 cc. pipette graduated to 1/10 cc. 10 cc. pipette graduated to 1/10 cc. 10 cc. glass cylinder Medicine dropper Koch's Old Tuberculin 1/2% and 1% dilution of Old Tuberculin in .85% sterile normal salt solution. To make 1% dilution, add .1 cc. Old Tuberculin to 9.9 cc. of diluent. 3. APPLICATION OF TEST: Patient sitting, with head thrown back Lower eyelid drawn slightly down and toward the nose--to form a small pouch of the lid; One drop of 1% or 1/2% instilled in that pouch and the lower lid moved up gently over the eye until the lids meet; Eye kept closed for one minute or so. 4. REACTION: Onset in 12 to 24 hours (may begin earlier); acme in 24 to 36 hours; duration of reaction--3 to 4 days or even longer (in severe cases). Some reactions are of short duration. 3 grades of reaction, according to Citron: 1. Reddening of caruncle and palpebral (lid) conjunctiva. 2. More intense reddening, with involvement of ocular (eyeball) conjunctiva, and increased secretion. 3. Very intense reddening of the whole conjunctiva, with much fibrinous and purulent secretion, etc. 5. TIME OF INSPECTION: 12 and 24 hours after instillation; then once a day. 6. CAUSE OF REACTION: Hyperaemia and exudation resulting from interaction between _instilled tuberculin_ and _antibodies in conjunctiva_ (bacteriolysin, according to Wolff-Eisner). 7. INTERPRETATION OF REACTION: Wolff-Eisner maintains that positive conjunctival tuberculin reaction means _active_ tuberculosis, a conclusion accepted by but a few. 8. FIELD OF APPLICATION OF CONJUNCTIVAL TUBERCULIN TEST: _Should not be used_; connected with _danger_ to the eye. Conjunctival test used very rarely at present. IV. PERCUTANEOUS TUBERCULIN TEST 1. SYNONYMS: Salve Test; Moro Test. 2. SALVE: Equal parts of Old Tuberculin and anhydrous lanolin. 3. APPLICATION OF TEST: Site: abdominal wall below ensiform process, _or_ breast below nipple, _or_ inner surface of forearm. Application: rub in with the finger (using moderate pressure) a small particle of salve about the size of a pea. Rub it in into an area about 5 cm.; rub 1 minute. 4. REACTION: In 24 to 48 hours--_either_ numerous small reddened spots which disappear in a few days, _or_ numerous small nodules, _or_ coalescing nodules on a red base, etc. 5. INTERPRETATION OF REACTION: