23,5 Leach et al.: Hookworm Infestation 457 



we have no deaths, but also that in no case treated under 

 our supervision have symptoms of intoxication developed that 

 called for treatment or that gave us the slightest anxiety. We 

 have felt such confidence in our results that we have not hesi- 

 tated «to treat many thousands of cases elsewhere in the Philip- 

 pines on precisely the same dose standards we employed with 

 these men. So far, there have been no accidents. 



MATERIAL AND METHODS 



In undertaking this study we laid down two basic principles 

 with respect to the employment of the drug. In the first place, 

 we determined to administer no carbon tetrachloride the purity 

 of which was subject to the slightest question. To that end 

 every lot of the drug that was used was purchased as a pure 

 product from a drug house of established reputation. Before 

 use, it was tested for impurities under the direction of Mr. 

 Wells. We take pleasure at this time, in extending our thanks 

 to Mr. Wells for his interest and cooperation. 



We think it opportune at this time to repeat the warning con- 

 tained in a memorandum kindly prepared for us by Mr. Wells, 

 in response to our request for information concerning the chem- 

 ical problems involved in the issuance of carbon tetrachloride 

 designed to be administered to human beings. We deem this 

 necessary because we have records of not less than three fatali- 

 ties in the Philippines that appear to be associated with the ad- 

 ministration of an impure drug. Unfortunately we could secure 

 only the barest details of these cases. We were informed that 

 the drug was purchased from a Manila pharmacy and was sent 

 to the user in a soda water bottle labeled "Carbon Tetrachloride, 

 C. P.," and was administered in good faith. Death in these 

 cases seems to have followed the development of symptoms 

 highly suggestive of drug intoxication. Mr. Wells has written 

 us as follows, under date of March 31, 1923: 



Carbon tetrachloride received by the Bureau of Science and often 

 marked "c. p." contains carbon disulphide, aldehydes, and traces of chlorides 

 and sulphur. A recent shipment of 1,000 liters contained an excessive 

 amount of carbon disulphide. 



The usual procedure for purification of this product depends upon the 

 impurities present but in full is as follows: 



The carbon tetrachloride is refluxed with an oxidizing solution of sul- 

 phuric acid and potassium dichromate, distilled off, treated with 15 per 

 cent sodium or potassium hydroxide solution with agitation, separated, 

 washed with water, dried with calcium chloride, and carefully redistilled 

 in glass. 



