INDUSTRIAL A N D ENGINEERING CHEAfISTRY
December, 1925
serving as guide posts for future work, may enlighten us with respect to the behavior of some of the arsenicals which we have today. (1) Arsonophthaleins and fluoresceins in which t h e arsonic acid group is attached directly t o one of the aromatic nuclei of the phthalein or fluorescein molecule. ( 2 ) Organic polyarsenides. (3) Aliphatic arsonic acids and arseno compounds. (4)Aromatic arsonic acids in which protein-like side chains have been attached t o the aromatic nucleus. ( 5 ) Unsymmetrical arseno compounds, particularly those in which one-half has the tryparsamide linkage and the other has the typical arsphenamine grouping : As=As
0 NH
As=As
j ”
OH
LHaC’O \NH~
OH
CHsC’O I ”\2
As=As
1271
sults would assist in disclosing any relations between constitution and physiological activity. (6) Development of a simple method or simplified technic for determining the minimum effective dose. At present, too much reliance is placed solely on toxicity determinations; therapeutic indices are, of course, much more valuable in comparing different compounds. (7) Further studies on the “so-called” habituation t o arsenic. (8) A continuation of the study of the mode of action of arsenicals in the body. E-Minor
Problems
I n synthesizing arsphenamines, the arsenic is usually introduced into the aromatic molecule by treating either aniline or phenol with arsenic acid. As a result of many investigations of these reactions, the yields have been raised only to about 30 per cent. It would be well, therefore, to continue the study of these arsonations. The development of a simple method of isolating the p-hydroxyphenylarsonic acid from the reaction mixture resulting from the arsonation of phenol would be a distinct advance.
Appendix Dr. Fourneau, of the Pasteur Institute, has shown a decided interest in the activities of this committee and has offered to make it possible for one or two American chemists to carry on research in his laboratory. Dr. Fourneau’s letter is published below, and it seems certain that it will be of considerable interest.
(6) Amino and amino-hydroxy derivatives of 4,4’-diarsonodiphenyl. (7) Dyes obtained from diamino-4,4’-diarsonodiphenyl. (8) Heterocyclic compounds in which a n arsenic atom is a member of t h e ring. (9) Heterocyclic compounds containing a n arsenical group (a) attached t o the ring, and ( b ) as part of a side chain. (10) The preparation of arsenicals of the betaine type which may be resolved into optically active isomers. C-Neoarsphenamine
The writer was forcibly impressed by the numerous statements that an impartial investigation of neoarsphenamine would be a valuable contribution to our knowledge of organic arsenicals. Certain of the commercial organizations engaged in the manufacture of these medicinals probably have a fairly complete understanding of the chemistry of this material, but they can hardly be expected to broadcast such information. The following problems have been assembled from suggestions recently submitted : (1) The development of methods whereby both the mono- and di-substitution products may be prepared uniformly and as pure compounds. Undoubtedly much of the work on neoarsphenamine has been done with impure mixtures. ( 2 ) The development of accurate methods for determining the composition of arsenical preparations which are mixtures. (3) A study of the chemical differences between various types of neoarsphenamine, and the relation of these differences to the toxicity and curative action of the materials. (4) The relation of the method of preparation and composition of neoarsphenamine t o its keeping qualities.
DEARMR. CHRISTIANSEN: I am replying rather tardily t o your letter of June, partly because it required a little reflection and partly because I have been very busy during t h e recent months. The following is my answer in as brief a form as possible: (1) I agree entirely with your opinion t h a t a spirit of collaboration is necessary among those who are studying arsenicals. (2) I consider t h a t a t present the field of arsenicals is the most important of all those which have furnished medicinals t o combat infectious diseases. I believe in, particular t h a t in this series one will find a remedy for malaria. (3) I do not believe i t would be feasible for collaborators t o be separated b y great distances. We should, in fact, follow the work of the chemists who are working with us. Each day w e modify our original conceptions, a n d in reality if we are able t o furnish a theme of research, it can only be rather vague. I n my own laboratory, for example, we have t o modify our original concepts constantly.
I should like t o make the following proposition. I have a very well-equipped laboratory, and I offer the opportunity to test the drugs which are discovered in my laboratory in all the fields of therapeutics. Our intimate relations with the colonies, where nearly all the doctors have taken a course at the Pasteur Institute, give us facilities which one may not encounter in any other institute. I would gladly take one or two American chemists knowing their profession and having sufficient means t o live in Paris (that is, about 1000 to 1500 francs per month) into my laboratory for the purpose of working with arsenicals. I doubt if any other type of collaboration would be more efficient than this one. I should add t h a t we would furnish all the apparatus and materials. With kindest regards.
E. FOURNEAU
D-Pharmacological
(1) A quantitative study of the relative therapeutic value of different arsenical, mercurial, antimonial, and bismuth compounds in the treatment of syphilis and trypanosomiasis. ( 2 ) Standardization of criteria of relative therapeutic efficiency. ( 3 ) Complete pharmacological, toxicological, and therapeutic studies of all new arsenicals. Many of the chemical researches in the field of arsenicals have been carried on without any collaboration with pharmacologists. Consequently, our knowledge is often incomplete, and it may be t h a t data of great importance have been lost by this lack of cooperation. (4) A more comprehensive study of the therapeutic properties of some of the arsenicals already known. (5). A study of the distribution and excretion of arsonic acids, arsenious oxides, and arseno compounds. This study should be made in conjunction with the studies listed in Section A, and in both cases the same compounds should be used. These re-
Another Claim for Discovery of Missing Element 75 Professor Jaroslav Heyrovsky, professor of physical chemistry of Charles University, Prague, and Professor Doleysek, of the Prague Academy of Sciences, claim that they have discovered the missing chemicaI element 75. They have called the element “bohemium,” in honor of Bohemia, and claim t o have discovered it as an impurity in magnesium through the use of t h e mercury drop electroscope. It will be recalled t h a t the discovery of element 75 was also claimed by Professor Walter Naddack, of the University of Berlin, and his co-workers, Otto Berg and Ida Tacke, last June through the use of X-ray analysis and spectra. They named the element “masurium.” No scientific data t o substantiate these claims have yet reached this office.
