IMMUNOCHEMICAL STUDIES OF THE PLANT PROTEINS 423 
The precipitated glutenin was now dissolved in 0.2 percent KOH 
and centrifugalized to remove a small part that would not dissolve. 
It was then precipitated again by neutralization with HCl, washed in 
water, several baths of 70 percent alcohol to remove all traces of 
gliadin, absolute alcohol, ether, and dried over sulphuric acid, giving 
a fine white powder soluble in o.oi M KOH. 
The following table shows the reactions obtained from these 
wheat protein preparations. The tests, the results of which are here 
recorded, were all done under my observation by Dr. I. C. Walker 
(nos. 1-15 inch). Dr. Turnbull (nos. 16-19 inch), Dr. J. L. Goodale 
(nos. 20-22 inch), Dr. Fritz B. Talbot (no. 23), and to them am I 
indebted for the use of their results. 
Briefly described, the skin test, by means of which these results 
were obtained, is done by making small scarifications in the skin of 
the inner side of the forearm and applying separately to these the dif- 
ferent proteins which are then moistened with o.oi M KOH. A 
reaction is considered positive when an edematous swelling, which is 
usually surrounded by a red areola, makes its appearance about the 
scratch within a few minutes after the protein is applied. The in- 
tensity of the reaction is gauged by comparison with a control scratch 
upon which nothing but a drop of o.oi M KOH has been put. For a 
more complete description of the test the reader is referred to the 
publications of the above mentioned investigators (Walker, this series 
no. V '17, Turnbull '16, Goodale '16, Talbot '16). 
In recording these results zb is used to indicate a reaction scarcely 
stronger than the control and should probably very often be regarded 
as negative; + represents a quite definite reaction and the intensity 
of the reaction is represented in an arbitrary fashion by the number 
of plus signs, 4+ representing an edema about the size of a silver 
dollar. The size of the reactions alone, however, is a very inadequate 
comparison index of the anaphylactic activity of the proteins in 
question. For this reason the proteins were dissolved in o.oi M KOH 
at a concentration of i percent and from this solution dilutions were 
made, in the same medium, in the series I : 100, I : 1,000, i : 10,000, 
etc., and wherever possible the tests were repeated using the dilutions 
instead of the dry proteins. Wherever this was done the lowest con- 
centration to give a reaction is recorded in the table together with the 
size of the reaction. 
In all, about seventy patients were tested, but only those are 
