494 PATHOGENIC MICROORGANISMS 



may be nausea, a chill, rapid pulse, and general malaise. Locally 

 visible tuberculous processes, such as lupus, lymph nodes, etc., may 

 become more tender or swollen, and if the tuberculosis is pulmonary, 

 there may be coughing and increased expectoration. The tempera- 

 tures of persons subjected to the test should be taken regularly for 

 three or four days before tuberculin is used. 



Ophthalmo-Tuberculin Reaction. — ^Wolff -Eisner ^ and, soon after 

 him, Caknette ^ proposed a method of using tuberculin for diagnostic 

 purposes by instillation into the conjunctival sac. In tuberculous 

 patients this process is followed by a sharp conjunctival congestion last- 

 ing from one to several days. 



The preparation used for this purpose is produced in the following 

 way: 



"Old Tuberculin" is treated with double the quantity of 95 per 

 cent alcohol, and the precipitate allowed to settle and the alcohol then 

 filtered off through paper. The sediment is washed with 70 per cent 

 alcohol until the filtrate runs clear, then pressed between layers of 

 filter paper to remove excess of moisture, scraped into a dish, dried 

 in vacuo over H2SO4, and broken up in a mortar under a hood. 



Solutions of the powder are made in sterile normal salt solution, 1 

 per cent by weight, boiled and filtered. The solutions are used in 

 strengths of 0.5 to 1 per cent, a drop of which is instilled into the con- 

 junctival sac' 



Cutaneous Tuberculin Reaction. — Von Pirquet ^ has suggested the 

 cutaneous use of tuberculin for diagnostic purposes. A 25 per cent 

 solution of "Old Tuberculin" is made in the following way: 



Tuberculin 1 



Salt solution 2 



5 per cent carbolic acid in glycerin 1 



After sterilization of the patient's forearm, two drops of this solution 

 are placed upon the skin about 6 cm. apart. Within each of these drops 

 scarification is done, and the skin between them is scarified as a con- 

 trol. Within twenty-four to forty-eight hours, in tuberculous patients, 

 erythema, small papules, and herpetiform vesicles will appear. The 

 reaction is irregular and more reliable in children than in adults. Ac- 



1 Wolf-Eisner, Berl. med. Gesell., May 15, 1907. 



^ Calmetle, Acad, des sci., June 17, 1907. 



^ Method in use at Saranac and kindly communicated by Dr. Baldwin. 



'V. Pirquet, Berl. klin. Woch., xx, 1907; Med. Klinik, xl,. 1907. 



