Positive reaction is assumed to indicate existing tuberculous infection somewhere in the body; does not indicate that the process is active. 6. FIELD OF APPLICATION OF PERCUTANEOUS TUBERCULIN TEST: The percutaneous tuberculin test fails in a large proportion of tuberculosis cases. The test is used rarely at present. LIGNIERES TEST A modification of the Moro Test Instead of salve, a few drops of Old Tuberculin rubbed in. Used rarely at present. V. INTRACUTANEOUS TUBERCULIN TEST 1. SYNONYMS--Mantoux Test 2. APPLICATION OF TEST: Injection into skin (needle parallel to skin) of 1/100 mg. of Old Tuberculin (according to Mantoux). 3. REACTION: Onset in a few hours, well developed in 24 hours, acme in 48 hours. Reaction consists of a central nodule surrounded by a halo of redness. This is the intracutaneous test as originally suggested by Mantoux. CONCLUSIONS Comparing the various tuberculin tests we find that: 1 _The Subcutaneous Tuberculin Test_ has the advantage of focal reaction, disclosing in a certain percentage of cases the seat of the disease. The subcutaneous test should, however, never be employed unless _as a last resort_, and then only after all other methods of diagnosis are exhausted and an absolute diagnosis is very essential. In the vast majority of suspected cases of tuberculosis, thorough study of the history of the case, combined with thorough physical examination, furnishes all the necessary data for diagnosis and an efficient plan of treatment. 2 _The Cutaneous Tuberculin Test_ is a very efficient diagnostic measure in children under two years of age in whom a positive cutaneous tuberculin reaction indicates active disease. Positive cutaneous tuberculin reaction in adults indicates existence of a tuberculous process, somewhere in the body; it does not indicate that the process is active. Negative cutaneous tuberculin reaction is one of the corroborative evidences of absence of tuberculosis, unless reaction is prevented by very advanced disease or tolerance to tuberculin established by tuberculin treatment. 3 Thorough study of the history and thorough physical examination of each individual case are more important and should precede the application of any test. FOOTNOTES: [1] For illustration, see Knopf, "Tuberculosis," Chap. IV, page 67. [2] See Carrington, "Fresh Air and How to Use It," Chap. II, page 29. [3] For illustration, see Carrington, "Fresh Air and How to Use It," Chap. II, page 37. [4] For illustration, see Carrington, "Fresh Air and How to Use It," Chap. VIII, page 128. [5] For illustration, see Knopf, "Tuberculosis," Chap. IV, page 58. [6] For illustration, see Carrington, "Fresh Air and How to Use It," Chap. VII, page 108. [7] See previous footnote. [8] For illustration, see Journal of Outdoor Life, January 1914.