298 proceedings: philosophical society 



The 111th meeting of the Academy was held in the Auditorium of 

 the New National Museum, Friday afternoon April 28, 1916, with Presi- 

 dent L. O. Howard in the chair and about 200 persons present. Dr. 

 Carl Voegtlin, of the U. S. Public Health Service, Washington, D. 

 C, gave an illustrated lecture on The relation of the vitamines to nutri- 

 tion in health and disease. It formerly was supposed that any diet 

 was sufficient if it contained enough proteins, fats, carbohydrates, and 

 salts; but it is now known that under certain circumstances, even with 

 an abundance of food, nutrition diseases such as scurvy and beri-beri 

 are apt to develop. Beri-beri, for instance, is likely to develop when 

 polished rice forms the exclusive diet, but does not occur when the rice 

 is unpolished and even disappears when the patient is given rice-bran 

 or certain bran extracts. It follows that the bran contains something 

 essential to health which the rice-grain proper does not. Such prod- 

 ucts are found in many grains and plants and are known as vitamines, 

 that is, basic organic compounds essential to life. These compounds 

 are produced by plants only, but very unequally. In the animal body 

 they are found most abundantly in the spinal cord and other nerve 

 tissue, 



W. J. Humphreys, Recording Secretary. 



THE PHILOSOPHICAL SOCIETY OF WASHINGTON 



The 770th meeting was held on March' 18, 1916, at the Cosmos Club; 

 President Briggs in the chair, 46 persons present. The minutes of the 

 768th and 769th meetings were read in abstract and approved. The 

 Secretary reported the action of the General Committee adopting an 

 amendment to Article V of the By-laws to class as life members all 

 who have maintained an active membership in the Society for 40 years. 

 Messrs. Abbe, Clarke, Dall, and Gilbert have been designated life 

 members under this amendment. The treasurer read a communica- 

 tion from the Secretary General of the Committee of the International 

 Association of Academies in charge of the publication of the Annual 

 Tables of Constants and Numerical Data expressing thanks for the con- 

 tinued financial aid received from the Society. 



Mr. H. C. Dickinson presented an illustrated communication giv- 

 ing the results of an investigation in collaboration with Mr. M. S. Van 

 Dusen on Heat transmission through air layers. Measurements were 

 made of the heat transmission in unit time per unit area and unit tem- 

 perature difference through vertical air layers inclosed between plane 

 nickel-plated copper plates, for heights (h) of from 3 to 60 cm., for dis- 

 tances (D) between the plates of from 1 to 60 mm., and for differences 

 of temperature (A) of from 5° to 30° centigrade. The effect of direct 

 radiation was determined and all observations were corrected to include 

 only transmission due to gas conduction, quiet convection, and tur- 

 bulent convection. Transmission decreases to a minimum for increas- 

 ing D and for greater widths becomes nearly constant, the position of 

 minimum depending upon h. Transmission decreases with increasing 



