518 THE ANAEROBIC BACTERIA 
Intrathecal administration is ordinarily practiced by removing 20 cc. 
of spinal fluid from the patient and very slowly replacing the fluid 
by the warmed (38° C.) tetanus antitoxin carefully watching for symp- 
toms of pressure or collapse.^ The administration of antitetanic serum 
as a preventive measure before certain operations is a procedure that 
has much to commend it. 
C'almette has used dried tetanus antitoxin to dust the navel of the 
new-born in the tropics and the deaths from tetanus neonatorum have 
been very greatly reduced by this procedure."^ Bochenheimer^ has 
made a dressing composed of an ointment mixed with tetanus anti- 
toxin, which is also said to be very efficient not only for the treatment 
of the umbilicus of the new-born, but for other wounds as well. 
Tetanus antitoxin is less efficient than the diphtheria antitoxin for 
several reasons. (1) The diphtheria antitoxin has a greater affinity 
for its toxin in vitro than the tetanus antitoxin has for tetanus toxin. 
(2) Diphtheria toxin appears to infect principally the parenchymatous 
and lymphatic organs. The cells comprising these organs are less 
susceptible to toxin than are nerve cells which are energetically attacked 
by tetanus toxin. (3) The diphtheria toxin has less affinity for par- 
enchymatous cells than it has for its antitoxin, and the diphtheria 
toxin, furthermore, circulates in the blood stream where the antitoxin 
also circulates when it is injected. Treatment, therefore, with diph- 
theria toxin is successful even after symptoms develop. (4) Tetanus 
toxin has a considerably greater affinity for nerve cells than it has for 
its own antitoxin. The tetanus antitoxin is "picked up" by the end- 
organs of the nerves and reaches the central nervous system by the 
axis cylinders, while the antitoxin circulates in the blood and is not 
carried to the central nervous system by way of the nerves. Treatment 
with tetanus antitoxin, consequently, is rarely successful after symp- 
toms appear and practically never successful after the symptoms have 
been developed for twenty-four hours. 
The Tetanus Antitoxin Unit.— The tetanus antitoxin unit of the United 
States may be defined as "ten times the minimal quantity of tetanus 
antitoxin necessary to protect a 350 gm. guinea-pig against a standard 
dose of tetanus toxin obtained from the United States Public Health 
and Marine Hospital Laboratory. "'* It has theoretically the power to 
neutralize 1000 minimal lethal doses of tetanus toxin, and it has, con- 
sequently, ten times the theoretical strength of the diphtheria anti- 
toxin unit. 
Distribution of Tetanus Bacilli in Nature.— Under ordinary conditions 
the tetanus bacillus appears to be a saprophyte, and man is not neces- 
sary for its continued existence. The organisms are found very com- 
1 Bruce: Lancet, 1916, ii, 929; ibid., 1917, i, 680; Trans. Soc. Trop. Med. and Hyg., 
1917-1918, 11, 1. Leishman and Swallow: Lancet, 1917, i, 131. 
2 It must be remembered that the albuminous substances contained in the antitoxin, 
mixed with serum from the wound, make a favorable culture medium for many bacteria; 
the dressings must be sterile and watched carefully to safeguard the patient. 
3 Arch. f. klin. Chir., 1908, 87, Heft 4. 
* Hyg. Lab. Bull., No. 43, March, 1908. 
