584 EXPERIMENT STATION RECORD. [Vol.38 



in immune animals than in normal animals. Tlie leucocytes do not, how- 

 ever, penetrate the tissue as rapidly in the immune animals. The connective 

 tissue formation in normal rabbits is more rapid and more marked than in 

 immune animals. The penetration of the pieces in normal animals by con- 

 nective tissue cells is also more rapid." 



The significance of the difference between the reactions in normal and im- 

 mune animals has not yet been determined. 



Is there any quantitative relationship between antigen dose and antibody 

 production? E. T. H. Tsen {Joiir. Med. Research, 31 {1918), No. S, pp. S81-390, 

 figs. 2). — The question was investigated by intravenous injections of different 

 doses of sheep serum into rabbits and subcutaneous injections of different 

 doses of antityphoid vaccine into medical students. Examination was made 

 of the precipitin and agglutinin productions, respectively. 



The results seem to show that there is no quantitative relationship between 

 the antigen dose and antibody production. As much antibody can be produced 

 in response to the injection of small as to that of large doses of antigen. 

 Moreover, large doses of antigen are at times harmful through injury to the 

 cells, so that the animal either dies of intoxication or remains in a state of 

 lowered resistance with the production of little or no antibody. 



A comparison of the slow and rapid methods of antibody production con- 

 firmed the results of Gay and Fitzgerald, previously noted (E. S. R., 29, p. 

 581), that the rapid method is as efficient as the slow method. 



An experimental investigation of lipovaccines. — A preliminary note, E. R. 

 Whitmoee, E. a. Fennel, and W. F. Petersen {Jour. Amer. Med. Assoc., 70 

 {1918), No. 7, pp. Jt2'1-Jf31, fig. 1). — The preparation and methods of preservation 

 and administration of lipovaccines from typhoid, paratyphoid, pneumococcus, 

 meningococcus, and dysentery organisms are described with experimental data. 

 Although considering the work as purely preliminary, the authors feel that 

 the lipovaccine offers a number of advantages over the aqueous preparation, 

 including " the diminution of both the local and the systemic reaction, the 

 feasibility of giving sufficient vaccine at a single injection properly to immunize 

 the individual, the persistence in the individual of a focus from which the 

 immunization proceeds over a period of several months with a resulting length- 

 ening of the period of immunity, the actual detoxicating effects of certain lipoids 

 that can be incorporated in the vaccine, and the prevention of autolysis and 

 deterioration of the vaccine." 



The effect of high pressures on bacteria, W. P. Laeson, T. B. Haktzell, and 

 H. S. DiEHL {Jo%ir. Infect. Diseases, 22 {1918), No. 3, pp. 271-279).— This ar- 

 ticle reports the results of attempts to obtain the antigenic principle of bacteria 

 in a diffused state in order to make it less accessible to the phagocytes and 

 consequently capable of producing a higher degree of immunity than is ordi- 

 narily possible with bacterial antigens. 



It was found that a direct pressure of 6,000 atmospheres kills nonspore-form- 

 ing bacteria in 14 hours. A pressure of 12,000 atmospheres for the same length 

 of time is required to kill spores. Attempts to discover the mechanism of the 

 destruction of bacteria in this way resulted in the conclusion that the factor 

 which destroyed the organisms was the sudden change in the osmotic tension 

 of the fluid in which the bacteria were suspended. 



Filtrate of typhoid bacteria subjected to a direct load of 6,000 atmospheres 

 for 14 hours was found to be superior to the living culture as an immunizing 

 antigen. Bacteria killed by carbon dioxid were found to be excellent antigens. 



Identity of the toxins of different stuains of Bacillus welchii and factors 

 influencing their production in vitro, C. G. Bxtll and Ida W. Peitchetx 



