VENOMS, TOXINS, ANTIBODIES 379 



and antibodies are more sensitive to most types of radiant energy than 

 are most enzymes, simple protein solutions, etc. Even this estimate 

 requires the reservation that it may only be that immunological methods 

 are more sensitive indicators of change than are the methods in use in 

 other fields. 



b. The relative lability of various toxins, etc., under irradiation might 

 again be stated with some confidence if we had pure substances having 

 known optical characteristics, and standard conditions of (mono- 

 chromatic) irradiation. A table can be made for all experiments with 

 quartz-mercury-arc lamps, arbitrary guesses being made as to corrections 

 to be introduced for wattage, current density and temperature in the arc 

 (which affect the spectral composition of the light), distance from source, 

 thickness of absorbing layer, and effectiveness of stirring, etc., and 

 figures thus deduced which do not vary more than about tenfold for any 

 one substance. For some substances such as alexin the margin of doubt 

 is not so appalling, but nevertheless such a tabulation is not worth 

 publishing. Perhaps the greatest obstacle to progress in this field is the 

 obstinacy with which its workers, mostly ignorant of the basic principles 

 of physical chemistry, cling to worthless criteria such as "complete 

 hemolysis" or "completely destroyed" as end points, leaving the reader 

 to guess whether the process is, for example, 0.9 or 0.9999 complete. 



We are thus left with the following slender harvest: in mammalian 

 sera similarly diluted, under roughly equal intensity of ultra-violet 

 irradiation, alexin is half inactivated in about 0.5 min., those properties 

 including lysins, agglutinins, precipitins, opsonins, etc., which are rather 

 generally believed to be simply different measures of a single thing, are 

 half inactivated in 2 to 20 min., and antitoxin in perhaps 10 min. Venoms 

 and plant toxins have always been irradiated in rather transparent media, 

 often in 1 :10,000 dilution, and comparisons with serum media would rest 

 on treacherous ground. In these media they are half inactivated in 

 perhaps 2 to 3 min. Exception must be made for moray serum, irradiated 

 undiluted, which might on the same basis as antisera, be guessed to be 

 half inactivated in about 4 min. It should also be noted that Phisalix 

 and Pasteur (129, 131) were unable to detoxicate the venom or serum 

 of the asp (Vipera aspis) by ultra-violet irradiation. This result is so 

 out of line with all other known facts that further investigation is needed. 

 Bacterial toxins in bouillon media require perhaps a few seconds to 

 5 min. ; purified toxins are more sensitive. 



To summarize: it seems probable that alexin is the most sensitive to 

 ultra-violet irradiation, antibodies somewhat less so, and, allowing for the 

 greater transparency of the media, venoms and toxins about the same as 

 antibodies or more stabile. Data on other antigens do not justify even a 

 guess, and it must be remembered that the above statement is only a 

 guess. The order of stability as far as concerns the actual reactivity of 



