13 
GUINEA PIGS MAY BE SENSITIZED IN THE EYE. 
So far as may be judged from the following experiment, it 
appears that normal horse serum dropped upon the eye of a guinea 
pig may sensitize it to a second injection of horse serum given after 
an interval of seventeen days. 
Table No. 7. — Ocular sensitization. 
G.P. 
No. 
First injection. 
Inter- 
val in 
days. 
Second injection. 
Result. 
1340 
1 drop normal horse serum into 
17 
6 c. c. normal horse (roan) serum 
Mild symptoms. 
each eye. 
intraperitcneally. 
1341 
do 
28 
6 c. c. normal horse (roan) serum 
No symptoms. 
subcutaneously. 
1342 
do 
28 
do 
No symptoms. 
ATTEMPTS TO SENSITIZE GUINEA PIGS WITH PURE PROTEINS. 
We have assumed that it is a protein substance in the horse serum, 
egg-white, milk, vegetable extracts, etc., that we have tested which 
sensitizes guinea pigs and poisons them at the second injection. The 
substances used by us of course have a very complex composition, so 
that it became desirable to use solutions of pure proteins for these 
tests. We are indebted to Dr. Lafayette B. Mendel, New Haven, 
Conn., for a quantity of edestin and excelsin, which are protein sub- 
stances obtained in a chemically pure crystalline state. Our tests 
with these two particular proteins resulted negatively, due probably 
to the difficulty of obtaining a satisfactory solution of them. 
Table No. 8. — Pure protein. 
G. P. 
No. 
First injection. 
Inter- 1 
val in 
days. 
Second injection. 
Result. 
1393 
0.1 gm. edestin subcutaneously. . . 
21 
3 c. c. 1 per cent solution edestin 
in 10 per cent NaCl subcutane- 
ously. 
No symptoms. 
1394 
0.01 gm. edestin subcutaneously. . 
21 
do 
No symptoms. 
1395 
0.001 gm. edestin subcutaneously. 
21 
do 
No symptoms. 
1396 
0.1 gm. edestin subcutaneously. . . 
22 
6 c. c. 1 per cent solution edestin 
in 10 per cent NaCl subcutane- 
ously. 
No symptoms. 
1397 
0.01 gm. edestin subcutaneously. . 
22 
do 
No symptoms. 
1398 
0.001 gm, edestin subcutaneously. 
22 
do 
No symptoms. 
1399 
0.1 gm. excelsin subcutaneously. . . 
21 
3 c. c. 1 per cent solution excelsin 
in 10 per cent NaCl subcutane- 
ously. 
Symptoms^?). 
1400 
0.01 gm. excelsin subcutaneously. . 
21 
do 
Symptoms (?). 
1401 
0.001 gm. excelsin subcutaneously 
21 
4 c. c. 1 per cent solution excelsin 
in 10 per cent NaCl subcutane- 
ously. 
Symptoms (?). 
1402 
0.1 gm. excelsin subcutaneously. . . 
22 
6 c. c. 1 per cent solution excelsin 
in 10 per cent NaCl subcutane- 
ously. 
No symptoms. 
1403 
0.01 gm. excelsin subcutaneously. . 
22 
do 
No symptoms. 
