370 INFECTION AND IMMUNITY 



increasing doses of the antigen, in this case horse serum, over an 

 interval of a number of hours. Cole 55 states that it is safe to begin 

 with a subcutaneous injection of 0.025 c.c. of scrum, and at one-half 

 hour intervals thereafter, giving further doses, doubling the amount 

 each time. Adverse symptoms should of course lead to still greater 

 care and a lengthening of the interval. If by this careful method 

 finally 1 c.c. has been given at a dose without adverse symptoms, 

 0.1 c.c. may be given intravenously, and continued every one-half hour 

 with double the dose. Cole recommends continuing this careful 

 procedure until about 25 c.c. total of the serum has been given. He 

 then waits about four days, and gives the remainder of the dose. 



It stands to reason that no absolute rules for such a procedure 

 can be given and that after the general principle has been under- 

 stood, the individual physician must be guided by close observation 

 of the patient and familiarity with the symptoms to be expected. 



The adverse symptoms to be expected are immediate respiratory 

 distress, rapidity of the pulse, and there may be coughing. 



In finally giving the serum, in such cases, in the larger quantities, 

 it should be diluted with sterile salt solution by at least one-half, 

 and may be so given by gravity that the first 10 c.c. should occupy 

 about ten minutes. 



HAY FEVER, URTICARIA, ETC. The clinical condition spoken of as 

 hay fever, asthmatic attacks called forth by apparent hypersus- 

 ceptibility to certain kinds of dust, the emanation of animals, etc., 

 etc., cannot at present be classified clearly with true anaphylaxis 

 because of certain apparent differences from ordinary anaphylactic 

 phenomena which cannot be ignored. Dunbar 56 at first regarded 

 the susceptibility to pollen or hay fever as due to a toxin. This, 

 however, is not tenable on present experimental evidence. The toxin 

 idea is not tenable because of the fact that normal insusceptible 

 individuals do not react to many times the amounts to which the 

 hay fever patients respond. Numerous studies upon the inheritability 

 of the hay fever tendency seemed to show that a tendency to hyper- 

 sensitiveness of this kind may be hereditary, an observation which 

 in the train of a number of other investigators has recently been 

 corroborated by Cooke and Vander Veer. 57 They seem to believe 



55 Cole, Monograph of the Eock Inst., 1917, No. 7. 



58 Dunbar, cited from Doerr, Kolle and Wassermann Hamlbiich, Edit. 2. 



67 Coolce and Vander Veer, J. of Immun. I, 1916, 201. 



