SERUM THERAPY 559 



(iv) Grassberger and Schattenfroh find that the toxins produced by different 

 strains of the Bacillus chauvcei are not all of the same degree of toxicity, and 

 that in order to prepare a satisfactory toxin it is necessary to select a strain 

 carefully and adapt it to a medium suitable for toxin production. These 

 investigators recommended a lactose-broth containing calcium carbonate as 

 the best medium on which to grow strains which ferment rapidly, and broth 

 containing calcium lactate for strains which do not set up a violent fermenta- 

 tion since the toxicity is materially diminished by filtration (Leclainche and 

 Vallee) it is necessary to work with decanted cultures. In this way Grass- 

 berger and Schattenfroh obtain a toxin which is fatal to guinea-pigs in 2-4 

 days in doses of O'Ol c.c. inoculated sub-cutaneously (normal toxin). Rabbits, 

 monkeys, dogs, mice, fowls and pigeons are also susceptible to the toxin : 

 inoculation of 40 c.c. beneath the skin of a calf is fatal in 2-6 days : sheep 

 succumb to the inoculation of 2 c.c. 



4. Serum therapy. 



(i) Kitt was the first to make experiments on the serum therapy of symp- 

 tomatic anthrax ; working with sheep and horses he inoculated the virus 

 first intra-venously and then sub-cutaneously. The serum of these animals, 

 in doses of 5-10 c.c. sub-cutaneously, protects sheep against a virulent 

 inoculation given 3 days to a week later. 



(ii) Dlinschmann increases the natural immunity of the rabbit by the 

 inoculation of increasing doses of the virus. The serum of the rabbit is 

 then both prophylactic and antitoxic for the guinea-pig, if given either 

 separately, before or at the same time as the virus, or if well mixed with the 

 latter. The serum however has no therapeutic property. 



(iii) Arloing immunized an heifer by inoculating it with increasing doses 

 of the virus over a period of 6 months'. The animal was then immune to the 

 inoculation into the blood and connective tissues of very large quantities 

 of fluid from a local lesion. Its blood was found to possess prophylactic, 

 therapeutic and antitoxic properties. 



Arloing' s serum neutralizes double its weight of fresh virulent virus in vitro. 

 The mixture may be safely inoculated into sheep. 



If inoculated in doses of 10 c.c. into the connective tissues of another part of the 

 body it will, if administered at the same time, protect a sheep weighing 30 kg. against 

 a fatal dose of fresh virus. A similar result is obtained if one-tenth the dose be 

 inoculated intra-venously. 



The immunity conferred is of short duration : it is still in evidence on the fourth 

 day but has completely disappeared at the end of a week. If however the inocula- 

 tion of the serum be followed by an ordinarily fatal dose of fresh virus a much more 

 stable immunity is established. 



The inoculation of the mixture of serum and virus produces few symptoms but does 

 not lead to any appreciable degree of immunity. Animals treated with the serum- 

 virus mixture survive the test inoculation rather longer than control animals but 

 always succumb in the end. 



The sub -cutaneous inoculation of a powerfully prophylactic serum arrests the 

 extension of a fatal inoculation in sheep, if given within 3 hours of the latter. The 

 same dose is effective if given intra-venously 9 hours after infection, but has no 

 effect after 12 hours. 



The properties seem to be preserved intact if the serum be rapidly dried in the air 

 in a thin layer at a temperature of 38 C. 



(iv) Leclainche and Vallee obtain an antiserum by hyper-immunizing 

 goats and horses. 



(a) Goats. First a virulent culture is inoculated into the veins, and then at 

 intervals of 10 days, 5, 10, and 15 c.c. of a filtered product obtained by crushing 



