In a controlled experiment to study the effect of the rate and
 volume of air inspired on a transient reflex vaso-constriction
 in the skin of the digits, 39 tests under various combinations
 of rate and volume of air inspired were obtained (Finney 1947).
 The end point of each test is whether or not vaso-constriction
 occurred.

  Finney, D.J. (1947). The estimation from individual records of 
  the relationship between dose and quantal response. Biometrika 34,
  320--334.

   volume rate  response        volume rate  response
   ----------------------------------------------------

   3.70  0.825  constrict       3.50  1.09   constrict
   1.25  2.50   constrict       0.75  1.50   constrict
   0.80  3.20   constrict       0.70  3.50   constrict
   0.60  0.75   no_constrict    1.10  1.70   no_constrict
   0.90  0.75   no_constrict    0.90  0.45   no_constrict
   0.80  0.57   no_constrict    0.55  2.75   no_constrict
   0.60  3.00   no_constrict    1.40  2.33   constrict
   0.75  3.75   constrict       2.30  1.64   constrict
   3.20  1.60   constrict       0.85  1.415  constrict
   1.70  1.06   no_constrict    1.80  1.80   constrict
   0.40  2.00   no_constrict    0.95  1.36   no_constrict
   1.35  1.35   no_constrict    1.50  1.36   no_constrict
   1.60  1.78   constrict       0.60  1.50   no_constrict
   1.80  1.50   constrict       0.95  1.90   no_constrict
   1.90  0.95   constrict       1.60  0.40   no_constrict
   2.70  0.75   constrict       2.35  0.03   no_constrict
   1.10  1.83   no_constrict    1.10  2.20   constrict
   1.20  2.00   constrict       0.80  3.33   constrict
   0.95  1.90   no_constrict    0.75  1.90   no_constrict
   1.30  1.625  constrict

   ----------------------------------------------------


BUGS format


list(n=39, x1=c(3.7,3.5,1.25,0.75,0.8,0.7,0.6,1.1,0.9,0.9,0.8,0.55,0.6,1.4,0.75,2.3,3.2,
0.85,1.7,1.8,0.4,0.95,1.35,1.5,1.6,0.6,1.8,0.95,1.9,1.6,2.7,2.35,1.1,1.1,1.2,0.8,
0.95,0.75,1.3), x2=c(0.825,1.09,2.5,1.5,3.2,3.5,0.75,1.7,0.75,0.45,0.57,2.75,3.0,
2.33,3.75,1.64,1.6,1.415,1.06,1.8,2.0,1.36,1.35,1.36,1.78,1.5,1.5,1.9,0.95,0.4,
0.75,0.03,1.83,2.2,2.0,3.33,1.9,1.9,1.625), y=c(1,1,1,1,1,1,0,0,0,0,0,0,0,1,1,
1,1,1,0,1,0,0,0,0,1,0,1,0,1,0,1,0,0,1,1,1,0,0,1))