June 17, 1904.] 



SCIENCE. 



929 



The symbol h is used because, altbougb it is 

 numerically equal to the ratio of the electrical 

 units, it has not the dimensions of- velocity. 



The new gravitational equation may be 

 written 



The numerical value of G is the reciprocal 

 of the square of the velocity of light. 

 Putting 



Vc 



we may compare it with the well-known rela- 

 tion 



_ 1 



~V'iIk' 



On the electromagnetic system /t = 1, so 

 1 



^^ = "7=' 



Vk 



the above equation may be written 



where X has the numerical value of the dielec- 

 tric constant of the ether, but it is not a 

 quantity of the same kind. 



This rather remarkable relation between the 

 gravitational constant and the constant of the 

 ether is very suggestive. The only ratio e/m 

 that will give this result is the one above used. 

 It is also the most pro'bable experimental value. 



It appears to me that this coincidence can 

 hardly be accidental. 



If mass is electromagnetic, then the unit of 

 mass here used is the rational unit, and the 

 constant of mass attraction might be expected 

 to be related to the constants of the ether. 



The above result not only suggests that 

 matter is electrical in constitution, but that 

 gravitational force is the same in kind if not 

 in degree with electrical forces, and that they 

 act in, a common medium. 



It may be interesting to point out the rela- 

 tive magnitudes of electrical and gravitational 

 forces. 



The gravitational force is 



and the electrical force between the electrici- 

 ties contained in the masses M, M^ if they 

 were set free is 



^ K r-" ' 

 From which the ratio of electrical to gravi- 

 tational force is 



-^=(3X10"')*. 



Bergen Davis. 

 Phoenix Physical Labokatort, 

 Columbia UNnrEKSiTY, 

 May 28, 1904. 



F=X- 



M, 3P 



THE BOYAL COMMISSION ON 

 TUBERCULOSIS. 



The commission consisting of Sir Michael 

 Poster, M.P. (chairman). Professor G. S. 

 Woodhead, Professor Sidney Martin, Pro- 

 fessor McPadyean and Professor E. W. Boyce 

 has presented an ad interim report. It says: 



" After duly considering the matter, we 

 came to the conclusion that it would be de- 

 sirable not to begin the inquiry by taking evi- 

 dence — that is to say, by collecting the opin- 

 ions of others (though this might be desirable 

 at a later stage), but to attack the problem 

 laid before us by conducting experimental in- 

 vestigations of our own. 



" The first line of inquiry upon which we 

 entered may be stated as follows: What are 

 the effects produced by introducing into the 

 body of the bovine animal (calf, heifer, cow), 

 either through the alimentary canal as food, 

 or directly into the tissues by subcutaneous 

 or other injection, tuberculous material of 

 human origin, i. e., material containing living 

 tubercle bacilli obtained from various cases 

 of tuberculous disease in human beings, and 

 how far do these effects resemble or differ 

 from the effects produced by introducing into 

 the bovine animal, under conditions as similar 

 as possible, tuberculous material of bovine 

 origin, i. e., material containing living tu- 

 bercle bacilli obtained from cases of tubercu- 

 lous disease in the cow, calf or ox? 



" We have up to the present made use in 

 the above inquiry of more than twenty dif- 

 ferent ' strains ' of tuberculous material of 

 human origin — that is to say, of material 



