202 APPLIED IMMUNOLOGY 



the previous intolerant inoculation. Again the dosage 

 ascends the scale, and this time will probably pass be- 

 yond the size of the former intolerant injection with- 

 out harmful effect. Occasionally, a patient will be en- 

 countered exhibiting tuberculin hyper susceptibility. 

 This does not refer to the ordinary response to a full- 

 sized dose of tuberculin, but such a state as is seen 

 when, after the reduction of the dose to one-half, the 

 reaction reappears, and after a week or ten days with 

 a further reduction to one-tenth, an even greater re- 

 action occurs. This supersensitiveness to tuberculin 

 can be overcome and immunization resumed by sus- 

 pending all inoculations for three or four weeks, then 

 beginning far down the scale of dosage; that is, one- 

 thousandth of the former inoculation. 



Experience has taught that most patients first 

 show reactions to doses of tenths and hundredths of a 

 milligramme. Consequently, when doses of these or 

 larger sizes are administered, they should be spaced 

 by a week or ten days instead of three or five days as 

 is the flexible rule when administering the early small 

 doses. 



An all-important thought for the tuberculin thera- 

 peutist to bear constantly in mind is that in the average 

 case it will require six to eight months to reach large 

 immunizing doses; if the patient be hypersensitive the 



