264 HOOKWORMS 



and the slow absorption through the intestinal walls, Hall and 

 Foster strongly advise giving castor oil with the chenopodium 

 and also afterward; this gives a maximum of both efficacy and 

 safety. The usual method of giving oil of chenopodium is five 

 to 15 drops at two hour intervals; each dose should be accom- 

 panied by castor oil. 



A number of investigators have pointed out the superior effect 

 of oil of chenopodium when given with chloroform. Hall and 

 Foster, by means of extensive experiments on dogs, have demon- 

 strated that chloroform itself is more efficient against hookworms 

 than any other drug with which they have experimented, and they 

 could find no evidence of superior efficiency of a combined use 

 of both drugs, except in case of accompanying infection with 

 Ascaris, against which oil of chenopodium is particularly effec- 

 tive. Chloroform dissolved in castor oil can be given internally 

 in from three to four gram doses with as great a degree of safety 

 as can other drugs in common use for worms, its safety lying in 

 its rapid elimination from the system. A dose of chloroform 

 should not be repeated, however, in less than three weeks, since it 

 does some temporary damage to the liver which may not be 

 completely repaired in less than that time. 



Beta-naphthol is considered by some physicians better than 

 thymol, especially when distributed to laborers for use without 

 medical supervision, since there is less chance of bad results, and 

 it can be taken safely by an ignorant person with a few simple 

 directions. This drug is used for treatment of coolie laborers 

 in Ceylon, and new consignments of coolies are treated with it 

 whether infected or not, since a great majority of them are 

 parasitized. 



Male fern is sometimes used for expelling hookworms but is 

 more dangerous than either thymol or beta-naphthol, is more 

 expensive and is if anything less efficacious. Oil of eucalyptus 

 has also been used with some success. It has the advantage of 

 being less unpleasant and less dangerous than some of the other 

 drugs in common use. 



Prevention. — Methods of prevention of hookworm disease 

 are suggested by the mode of infection, namely, contact with 

 soil or water contaminated by infected faeces. The ways in 

 which such contact may be made are numerous, and vary with 

 the habits, occupation and wealth of the inhabitants. Plan- 



