48 SECTIONAL ADDRESSES. 



these are being tested systematically under arrangements made by the 

 permanent Committee. This work of national importance is a joint 

 effort of several groups of chemists working in different laboratories, so 

 that a wide and thorough search for greatly needed drugs and therapeutic 

 agents is in progress. 



The Teddington contribution to these researches may be classified 

 under the two following main headings : — 



1. Analogues of Bayer 205 or Fourneau 309. — -Last year,in his Presidential 

 Address to the Physiology Section of the British Association in South 

 Africa, Prof. W. E. Dixon referred to the serious ravages produced in that 

 continent by sleeping sickness (trypanosomiasis), and his admirable 

 survey of the position from the view point of chemotherapy renders 

 unnecessary any further elaboration of that aspect of the problem in the 

 j^resent summary. 



The activity of medicaments of the Bayer 205 or Fourneau 309 type 

 may depend more on the aggregate effect of the whole molecule rather 

 than on the presence in the molecule of any particular group or arrange- 

 ment. In this, as in other cases, there are no definite laws connecting 

 therapeutic activity and chemical structure. 



Compounds have been prepared in which the terminal aminonaphthalene- 

 disulphonic radicals have been replaced by analogous complexes derived 

 from aminocarbazole di- and tri-sulphonic acids or from the disulphonic 

 acids of aminofluorene and of aminofluorenone, but so far the effect of 

 this substitution has not been encouraging. The possibility of a beneficial 

 introduction of arsenic into the fluorene nucleus has, however, been 

 considered, and experiment has shown that trypanocidal activity is 

 manifested when an arsinic acid radical is present in a fluorene molecule 

 in conjunction with an amino-group. 



2. Organic Derivatives of Arsenic and Antimony. — During many 

 years organic arsenicals have received much attention, whereas organic 

 antimonials have not been subjected to the same careful scrutiny, 

 partly owing to the fact that they are more difficult to prepare in 

 a state of purity, and partly because the curative results have been less 

 promising. 



Nevertheless, since antimony in organic combination appears to 

 possess specific trypanocidal activity and some curative action in kala- 

 azar, experiments have been made in the Teddington laboratory on the 

 preparation of antimony analogues of the more successful arsenicals. 

 Tryparsamide (phenylglycine-amido-jo-arsinic acid) is used extensively in 

 treating trypanosomiasis, and its antimony analogue has been under 

 examination. In the more stable meta series, phenylglycine-amido-rw- 

 stibinic acid and certain allied compounds show a slight trypanocidal 

 effect. The antimony analogue of stovarsol (3-acetylamino-i-hydroxy- 

 phenyl arsinic acid), or more probably its internal dehydration product, 

 has also exhibited some therapeutic activity. 



Concurrently with this study of organic antimonials further experiments 

 have been made on organic arsenicals produced by condensing atoxyl 

 successively with succinic anhydride, and with a base such as ammonia, 

 methylamine, dimethylamine, piperidine, or aniline. Certain of these 

 derivatives have also exhibited a definite action on trypanosomes. 



