356 



SCIENCE 



[N. S. Vol. XLII. No. 1080 



(c) The serums of persons reacting strongly 

 positive were found to contain less than l/30th of 

 a unit per cubic centimeter of serum and fre- 

 quently none at all could be detected. 



These results corroborate those of Schick, Park 

 and Zingher. 



III. The duration of passive immunity to diph- 

 theria was studied in 106 persons by applying the 

 toxin skin test at varying intervals after the ad- 

 ministration of 1,250 units of antitoxin subcu- 

 taneously. 



The immunity conferred was apparently efficient 

 for ten days; after this interval antitoxin rapidly 

 disappeared, so that after four to six weeks the 

 immunity may be regarded as having entirely dis- 



IV. The toxin skin test was applied to 362 per- 

 sons in the various stages of scarlet fever and at 

 varying intervals of time following the subcutane- 

 ous injection of 2,500 units of antitoxin to study 

 the duration of passive immunity in scarlet fever. 



It was found that in scarlet fever passive im- 

 munity following an injection of diphtheria anti- 

 toxin is of shorter duration than that induced 

 among normal children in that 10 per cent, of the 

 former are susceptible within ten days after re- 

 ceiving antitoxin. 



V. The toxin test was also applied to 350 per- 

 sons, mostly children, suffering with diphtheria 

 and receiving from 10,000 to 100,000 units of anti- 

 toxin by subcutaneous injection. The high percent- 

 age of positive reactions during the first ten days 

 of the disease and after large doses of antitoxin 

 was quite surprising. As a general rule these oc- 

 curred among children with severe infections. It 

 was also found that patients were in general just 

 as susceptible after an attack of diphtheria as be- 

 fore; in other words, it would appear that the body 

 cells produce little or no homologous antitoxin and 

 the immune antitoxin is soon eliminated. 



VI. Practical experience with a small epidemic 

 of diphtheria has increased our confidence in the 

 toxin test as a means of detecting persons suscept- 

 ible to diphtheria. The chief practical value and 

 application of this test is the detection of non- 

 immune individuals and immunizing those only 

 instead of all persons indiscriminately. The reac- 

 tion has a special field of usefulness in hospitals 

 and wards for the care of children. 



While cultures were made of a large number of 

 the persons tested, there was found no constant re- 

 lation between the occurrence of diphtheria bacilli 

 in the upper air passages and the toxin test. 



The Mechanism of Abderhalden Beaction: J. 



Beonfenbeennek. 



When the placenta and serum of a pregnant indi- 

 vidual are placed on ice, instead of the thermostat, 

 the Ninhydrin reaction substances do not appear 

 in dialysate. The analysis of the ingredients, how- 

 ever, shows that both the serum and placenta 

 underwent changes — namely, placenta was sensi- 

 tized by fixing upon itself the specific substances 

 from the serum, and the serum was exhausted of 

 its specific substances. Such a serum, moreover, 

 when separated from placenta and transferred to 

 37° shows gradual deterioration of its comple- 

 ment, and parallel with it, the increase of dialyz- 

 able Ninhydrin reacting substances as the incuba- 

 tion at 37° goes on. Similar tendency to apparent 

 autodigestiou can be produced also in any normal 

 serum by placing it for a certain time in contact 

 with sensitized placenta (but not with normal 

 placenta). The absorption by the placenta of 

 specific constituents of pregnant serum is not due 

 to a mechanical absorption, but is strictly specific, 

 at least within certain quantitative limits. 



The action of this specific union between the 

 substratum and specific constituents of the serum 

 upon the residue of the serum is such that the 

 normal antitrypsin of the serum is inactivated (or 

 absorbed) and the normal proteolytic ferment is 

 set free. The action of this non-specific ferment 

 upon the residue of the serum is responsible for 

 the appearance of dialyzable substances. This ac- 

 tion of the ferment upon the serum can be ar- 

 rested in the Abderhalden test by the addition of 

 any substance acting as antitrypsin, as, for in- 

 stance, the serum albumen or serum lipoids, both 

 in the pure form and in the form of excess of 

 whole normal serum. The products of such auto- 

 digestion of the serum are toxic to homologous 

 animals, and their appearance can be made evi- 

 dent by the biological tests (anaphylaxis).^ 



Do Bacteria Produce Pyrogenio Poisons? D. H. 



Bergey, M.D. 



It is believed that the pyrogenio substances act 

 by (a) the stimulation of the heat-producing cen- 

 ters, or, (6) the inhibition of heat dissipation 

 through conduction, radiation and evaporation, or 

 (c) by the combination of these two processes. 



It is well known that the injection of animals 

 with distUled water, or with sterile bouillon leads 

 to fever production. Hence it was thought prob- 

 able that it might be possible to show the presence 

 of fever-producing poisons in a filtered bouillon 



1 The protocols will appear in one of the follow- 

 ing numbers of the J. of Exper. Med. 



