248 



Dr. J. E. Reynolds. On the 



[May 24 v 



It will be seen that the 1st string is thicker, and the 3rd thinner, 

 and the 4th much lighter than the theoretical values. Therefore the 

 tension of the 1st string would be greater, and that of the 3rd and 

 4th strings less than they should be in relation to that of the 2nd 

 string. The greater flexural rigidity of the 4th string will have a 

 small effect in the direction of making the vibrations quicker, and 

 therefore of making the tension required less. 



By means of a mechanical contrivance I found the weights neces- 

 sary to deflect the strings to the same amount when the violin was in 

 tune. The results agreed with the tensions which the sizes of the 

 strings showed they would require to give fifths. 



A violin strung with strings of the theoretical size was very un- 

 satisfactory in tone. 



The explanation of this departure of the sizes of the strings which 

 long experience has shown to be practically most suitable, from the 

 values they should have from theory, lies probably in the circumstance 

 that the height of the bridge is different for the different strings. It 

 is obvious, where the bridge is high, there is a greater downward 

 pressure. By this modification of the sizes of the strings there is not 

 the greater pressure on the 4th string side of the bridge, which would 

 otherwise be the case. On the contrary, the pressure is less, which 

 may assist the setting of the belly into vibration. There is also the 

 circumstance that the strings which go over a high part of the bridge 

 stand farther from the finger-board, and have therefore to be pressed 

 through a greater distance, which would require more force than is 

 required for the other strings, if the tension were not less. 



II. " Note on the Atomic Weight of Glucinmn or Beryllium." 

 By J. Emerson Reynolds, M.D., F.R.S. Received May 8, 

 1883. 



In the course of a paper by Professor Humpidge on the above subject, 

 recently read before the Society,* the author seeks to decide between 

 the atomic weight 9'2 for beryllium, resulting from my comparison of 

 the atomic heat of the element with that of silver and aluminium,"]' 

 and the value 13"8, arrived at by MM. Mlson and Pettersson by 

 determination of specific heat. J The difference between the two 

 possible atomic weights is so small, and the difficulties met with in 



* Bead April 12, 1883. 



f "Chemical News," rol. xxxt, p. 124, and vol. xlii, p. 273. A slight modifica- 

 tion of the method of comparison adopted is described in detail in the writer's 

 " Experimental Chemistry " (Longmans), Part I, p. 59. 



X " Proc. Koy. Soc," vol. 31, p. 37. 



