374 proceedings: biological society 



in a manner similar to sodiuha or potassium one would expect from the 

 analagous relations in the series of these elements to find ionization 

 determined by the quantum relation hp = eV when v is the limit of 

 the principal series v = 22,786. This requires a value of 7 = 2.81 

 volts, which cannot be considered in the light of the experimental data. 

 We believe that our work enables the prediction of a new series in 

 thallium. It is very possibly of the form v = 1.5 S— mP, a single 

 line series of low intensity converging at 1.5 S lying between 57,000 

 and 60,000. The highest convergence frequency of any series so far 

 known for thallium is 49,263. The present work again brings up the 

 question of the separate excitation of hues constituting a doublet. 

 Thallium appears to offer a fruitful field for work in this regard. 



Although the usual time of adjournment had arrived, it was moved 

 and carried that the program be completed, and Mr. P. D. Foote pre- 

 sented a paper on Electronic frequency and atomic number, which was 

 discussd by Dr. Swann. 



The meeting adjourned at 10.15 p.m. 



H. L. Curtis, Recording Secretary. 



BIOLOGICAL SOCIETY OF WASHINGTON 



The 584th regular meeting of the Society was held in the Assembly 

 Hall of the Cosmos Club, Saturday, April 20, 1918; called to order at 

 8 p.m. by President Rose; 35 persons present. 



General T. E. Wilcox stated that he had received a communication 

 from Ex-President Roosevelt in which he said he was presenting to the 

 Society an autograph copy of his book entitled A Booklover's Holiday 

 in the Open. Dr. Howard in this connection referred to the 277th 

 meeting of the Society when Theodore Roosevelt, then Assistant Secre- 

 tary of the Navy, attended for the first and only time a meeting of the 

 Biological Society of Washington. 



The regular program was as follows: 



Alex. Wetmore: Lead poisoning in waterfowl. Mr. Wetmore said 

 that lead poisoning in waterfowl has been known for a number of years 

 and recently has assumed considerable economic importance. Wild 

 ducks, whistling swans and a few other birds subject to this disease 

 pick up and swallow pellets of shot lying in the mud in marshes and 

 shallow lakes about old shooting bhnds. These shot are held in the 

 stomach and worn slowly away by grinding against bits of gravel taken 

 to aid digestion, so that small particles of lead are being steadily passed 

 out into the intestine, and in part absorbed. This causes a severe 

 diarrhoea, the feces are stained bright green, the birds are soon unable 

 to fly, and a slow paralysis sets in so that they become unable to stand. 

 Cases of long standing become much emaciated though the birds eat 

 eagerly. By experiment it was found that six number six shot when 

 swallowed were fatal in every instance, while in one instance one shot 

 of that size was sufficient to cause death from lead poisoning. It was 

 also shown that the trouble was due actually to lead and not to arsenic 



