TYPHOID FEVER. 491 



child reacted positively for thirty-three days after birth. 

 J. P. C. Griffith 1 has seen a similar case. Barber 2 

 reports a case of a woman who on the second day of 

 typhoid fever gave birth to a child whose blood, two 

 days later, gave the serum-reaction; subsequently the 

 infant had a slight fever and an attack of diarrhea. 

 Pepper and Stengel 3 mention a case in which the blood 

 of an infant gave positive agglutinative reactions. 

 Charrier and Apert 4 examined the tissues of an embryo 

 from a mother in the third week of typhoid fever. There 

 was a total absence of any agglutinating property in the 

 fetal organism, though it existed in the blood of the 

 placenta. 



VI. The Chemic Nature of the Agglutin. — Widal and 

 Sicard found that filtration through porcelain lessens the 

 quantity of agglutinative substance found in the body 

 fluids. The addition of 15 per cent, of sodium chlorid 

 precipitates fibrinogen, which carries down much of the 

 agglutinating substance with it. Further precipitation 

 with magnesium sulphate throws down the globulins 

 and more of the agglutinating substance. Dieulafoy 5 

 states that in milk the casein is the active principle. 

 Widal and Sicard conclude that it is not in the serum- 

 albumin, but in the globulins and fibrinogen that most 

 of the agglutin resides. In dialyzed liquids they found 

 the agglutinating substance absent. Achard and Ben- 

 saud, on the other hand, found it dialyzable. 



The agglutin has a marked resisting power, as is 

 shown bv the fact that it can be dried without change, 

 and is active after being sealed in tubes for months. It 

 resists decomposition for a time. Temperatures of 6o° 

 C. diminish its power, but it is only destroyed at 8o° C. 

 Sunlight has no effect upon it. 



VII. The relation of the agglutinating substance to the 



1 See Amer. Jour. Med. Sci., N. S., Jan. -June, 1897, vol. 113, p. 621. 

 1 New York Med. Jour., April 16, 1898, vol. lxvii., No. 16. 



5 Year- Book of Medicine, 1897. 



* Compt. rendu de la Soc. de Biol, de Paris, Jan. I, 1897. 



6 Bull. deTAcad. de Mid., 1896, 346. 



