WOODWARD, ON NOBERT's TEST-PLATE, 227 



^- „ , , -p.. , ,,. No. of lines to 



No. of baud. Distance of hues. ^1,^ millimeter. 



3 Ww „ 886 



4 .oV. ,, 1108 



5 W^o- ,, 1329 



6 -.^ „ 1550 



9 5 0*0 55 /v215 



10 3^^ „ 2437 



11 T,^ „ 2658 



12 -s-^ of a Paris line 2880 



13 Wwo » 3101 



14 -r^ „ 3323 



15 -^ow „ 3544 



16 vxuo „ 3T66 

 n Win. ,5 3987 



18 ^-r^ „ 4209 



19 -nnroir ,, 4430 



It will be seen tliat tlie lines of the 15th band of this plate 

 are the same distance apart as those of the 30th of the thirty- 

 band plate, and those of its 11th band are the same distance 

 apart as those of the 20th band in the twenty-band plate de- 

 scribed by Mr. Beck. 



Max Schnltze* has published a short account of some ob- 

 servations made by him with one of these new nineteen-band 

 plates, from which it appears that with central illumination 

 he succeeded in resolving the ninth band with two objectives, 

 viz., Hartnack's immersion system No. 10 and Merz's im- 

 mersion system -^. By oblique light he was able to see the 

 true lines in the 14th band. Mr. Charles Stodder,t in a re- 

 cent article on the Nobert plate, quotes the abbreviation of 

 Schultze's article in the ' Quarterly Journal of Microscopical 

 Science,' January, 1866, as follows : — " With oblique illumi- 

 nation he has not been able with any combination to get 

 beyond the 15th." This, I think, is hardly what was in- 

 tended by Schultze's somewhat ambiguous remark, "Bei 

 Schiefem Licht bin icli mit den besten systemen bis zur 

 15ten gruppe gekommen," which I understand to mean 

 that he resolved the 14th band, getting thus as far as to the 

 15th, which he did not resolve ; an interpretation which is 

 confirmed by the quotation made by Mr. Stodder in the same 



• ' Archiv fiir Mikroskopische Anatoniie/ erster band. Bonn, 1865, p. 

 305. 



t " Nobert's Test-plates and Modern Microscopes." ' American Natu- 

 ralist,' vol. ii, p. 97. 



