436 



SCIENCE 



[N. S. Vol. XLIII. No. 1108 



dX/\ =. D dh/B VI>' — A^ 

 where D is the grating space, B the path length 

 and dh the displacement of the second grating 

 G', normally to itself, between like rotational 

 phases of the two sodium lines. The second 

 member of the equation is roughly dh/B and 

 if dh. = .003 cm. is still guaranteed and 

 E = 300 cm. as in my apparatus, the limiting 

 resolving power is dX/X =■ 10"^ or .06 A. U. If 

 (iX/X^lQ-^ for the two sodium lines, dh^ 

 .3 cm., which is about what I found. 



An interesting application of the apparatus 

 (Fig. 1) or the other similar types may be sug- 

 gested. By half silvering the mirrors and pro- 

 viding a similar set heyond them, there should 

 be no difficulty of bringing the interferences 

 due to crossed rays, and to parallel rays, into 

 the field of the telescope, together. Strictly 

 homogeneous light (mercury arc) would be 

 needed to obviate the duplications of the 

 sodium arc. In such a case, therefore, the 

 parallel fringes could be used after the manner 

 of a vernier on the crossed fringes. One might 

 think of this with a view to a repetition of the 

 experiment of Miehelson and Morley, if this 

 experiment had not been so thoroughly carried 

 out by the original investigators. However, 

 the plan would be to rotate the apparatus, as 

 a whole, so that the two crossed rays would be 

 alternately in and at right angles to the earth's 

 motion, whereas the two parallel rays would 

 preserve the same relation to that motion. 

 Naturally the parallel and crossed paths would 

 in such a case have to be enlarged by multiple 

 reflection. Another favorable feature of the 

 reversed spectrum interferometer is the small 

 displacement, x, of micrometer per fringe. 

 This is X =. A/2(l + cos 6) cos o-/2, e being the 

 second angle of diffraction, a the sum of the 

 two. Hence roughly x =■ X/4, or the sensitive- 

 ness is about twice that of the customary 

 types of apparatus. Gael Baeus 



Brown University, 

 Pbovidence, R. I. 



SOCIETIES AND ACADEMIES 



THE BOTANICAL SOCIETY OF WASHINGTON 



The 107tli regular meeting of the Botanical So- 

 ciety of Washington was held in the Assembly 



Hall of the Cosmos Club, at 8 p.m., Tuesday, No- 

 vember 2, 1915. Forty-five members and six guests 

 were present. The following papers were pre- 

 sented : 



Belation of Catalase and Oxidases to Bespiration 

 in Plants (with lantern) : Chas. O. Apple- 

 man. (To be published in full as bulletin num- 

 ber 191 of the Maryland Agricultural Experi- 

 ment Station.) 



The chemical mechanism of respiration in plants 

 is very complex and imperfectly understood. 

 Enzyme action undoubtedly plays the most impor- 

 tant role. Among the enzymes which have been 

 assigned various functions in respiration, we find 

 the oxidases and catalase, although their relation 

 to this process is almost entirely hypothetical. 

 Respiration in potato tubers is not only greatly 

 accelerated by various artificial treatments, but is 

 subject to fluctuations under natural conditions, 

 such as greening and sprouting. The rate of res- 

 piration also varies in different parts of the same 

 tuber and tubers of different varieties. Since 

 these tubers also contain very active catalase and 

 oxidase, they were chosen as specially favorable 

 material to make a quantitative study of the rela- 

 tion of both catalase and oxidase activity to the 

 intensity of respiration. The data seem to justify 

 the following conclusions: 



1. The oxidase content in potato juice gives- no 

 indication of the intensity of respiration in the 

 tubers. In other words, there is no correlation be- 

 tween oxidase activity and the rate of respiration 

 in these organs. The author does not disclaim any 

 role of the demonstrable oxidases in respiration, 

 but they certainly are not the controlling factor 

 in regulating the rate of respiration in potato 

 tubers. 



2. Catalase activity in the potato juice shows a 

 very striking correlation with respiratory activity 

 in the tubers. 



Some Philippine Botanical Problems: E. D. 



Mebkill. 



To be published in full elsewhere. 

 Botanical Notes of a Trip to Japan: W. T. 



Swingle. 



To be published in full elsewhere. 



The 108th regular meeting of the Botanical So- 

 ciety of Washington was held in the Assembly 

 Hall of the Cosmos dub, at 8 p.m., Tuesday, De- 

 cember 7, 1915. Thirty-two members and three 

 guests were present. Messrs. A. T. Speare, James 

 Johnson, H. E. Eosen and H. C. Eose were elected 



