366 



SCIENCE. 



[N. S. Vol. XV. No. 375. 



action, contains one or even two hundred 

 times as much nascent oxygen. The au- 

 thors incline to the belief that the acetyl 

 and benzoyl ions are the active agents. 



Full papers upon this subject will ap- 

 pear in the Journal of Experimental Medi- 

 cine and in the American Journal of 

 Chemistry. 



The Etiology of Yellow Fever: Walter 

 Eeed, M.D., Surgeon U. S. Army, and 

 James Caeeoll, M.D., Contract Sur- 

 geon, U. S. Army. 



In former contributions to this subject 

 the authors have shown by observations 

 made on human beings that yellow fever 

 may be produced in the non-immune indi- 

 vidual either by the bite of the mosquito 

 (genus Stegomyia) or by the subcutaneous 

 injection of a small quantity of blood (0.5 

 to 2 c.c.) dra,wn from the general circula- 

 tion of a patient suffering with this disease. 

 Thus far, however, microscopic examina- 

 tion of the blood, as well as of the bodies 

 of infected mosquitoes, has proved nega- 

 tive. Cultures taken from the blood dur- 

 ing the active stages of the disease also 

 have yielded equally negative results. 

 Leaving out of consideration, therefore, 

 for the present the further microscopical 

 search for the specific agent, both in the 

 blood of the sick and in the bodies of 

 infected mosquitoes, the authors presented 

 some additional observations bearing on 

 the etiology of the disease. In conduct- 

 ing these experiments they have been 

 guided by the observations of Loeffler and 

 Frosch on the foot and mouth disease of 

 cattle, wherein it was conclusively demon- 

 strated that the specific agent of this dis- 

 ease was so small as to readily pass through 

 the pores of a porcelain filter. 



Adopting the same line of procedure, it 

 was ascertained that in yellow fever the 

 blood serum which has been filtered 

 through a Berkefeld laboratory filter is 



still capable of producing this disease when 

 subcutaneoiisly injected in small quantity 

 (1.5 c.c.) into non-immune human beings. 

 The authors reported an attack of yellow 

 fever after the usual period of incubation 

 in two out of three individuals thus 

 treated, and further stated that the blood 

 draAvn from one of the cases produced by 

 the injection of the filtered serum was ca- 

 pable of producing an attack in a third 

 individual, when injected in small quan- 

 tity; thus proving that the specific agent 

 had really passed through the filter. 

 They were also able to show that the 

 blood in yellow fever, when heated to a 

 temperature of 55 °C. for ten minutes is 

 quite innocuous if injected into susceptible 

 individuals. The specific agent of yellow 

 fever therefore is destroyed or markedly 

 attenuated by this degree of heat. 



Brain Abscess in Typhoid Fever due to 

 Bacillus typhosus: R. W. McClintock, 

 Rush Medical College, Chicago, 111. 

 There are mentioned in the literature up 

 to August, 1901, nineteen cases of menin- 

 gitis and five of abscess of the brain in 

 connection with typhoid fever. Bacillus 

 typhosus having been present in all the 

 cases of meningitis, but not found in any 

 case of abscess of the brain. 



Clinical History. — Temp. 101° a.m. to 

 104° P.M. In second week, rose spots 

 appearing on 8th day, nausea on taking 

 food; diazo-reaction questionable. Third 

 week, agglutination test probably positive. 

 Fifth week, 33d day, three epileptiform 

 convulsions at intervals of forty minutes, 

 followed by clonic spasms lasting five min- 

 utes, very much more marked on the right 

 side than on the left; pupils equal. Much 

 mental confusion in following two weeks, 

 with marked amnesic aphasia. During 

 eighth week, much better. In ninth week 

 spasms returned, with coma, terminating 

 in death on the 66th day. 



