278 PEOCEEDINGS OF SOCIETIES, 



Mr. Ladd described au addition lie had made to the microscope, 

 which he had found very useful in examining double axial crystals 

 with polarized light. Generally speaking of the apparatus employed, 

 the polariscope was a very expensive instrument. The little ajDpa- 

 ratus he had devised could be applied to any microscope with very 

 little trouble and cost. In the construction of it no new principle 

 was involved, although the application was new. Under the stage 

 of the microscope is placed a deep lens, beneath this another lens 

 not quite so deep, the ordinary Nichols' prism being added in the 

 usual manner. Above the stage this arrangement of lenses is re- 

 peated. The draw-tube of the microscope must have another lens ; 

 it is useful to focus the object of the draw-tube. The eye-i)iece used 

 was the ordinary A eye-piece, with the Nichols' prism over it in the 

 usual way. The advantage of having these lenses was that a wider 

 range of field was obtained, for by the arrangement described the two 

 axes of sugar could be brought into the field ; and it was well known 

 that it required a large view to take in those two axes. The arrange- 

 ment works better by daylight than by lamplight. He had seen 

 another instrument that day at Mr. Powell's, but it would not be 

 possible with that to bring in the two axes of sugar. 



The following note was read from Mr. Sufiblk : — 



" Clekemont Lodge, Park Street, Camberwell, 

 A2}ril 27, 1871. 



" Gentlemen, — I forward herewith preparations of vegetable fibres, 

 and chiefly from specimens supplied by Dr. John Forbes Watson, 

 Keporter on the Produce of India, and by whose kind permission I 

 am enabled to present the accompanying specimens. To these I have 

 added one or two received from Kew, and two slides of recent fibres 

 grown by myself. 



" The chief value of the whole is as a trade collection rather than 

 as a botanical one ; they are arranged as the duplicate series is in my 

 own cabinet. — Manufactured materials, not only including spun and 

 woven fabrics, but also fibres obtained therefrom. 



" I hope during the winter session to give the Society a paper in 

 explanation. 



" Yours truly, 



" W. T. Suffolk. 



" To THE Secretaries of the Royal 

 Microscopical Society." 



Dr. Braithwaite said, that as the number of fibres produced by the 

 vegetable kingdom useful for textile fabrics was increasing every year, 

 it was a very great advantage to have the actual notion of the nature 

 of the fibres produced by certain plants as objects of comparison when 

 working in that department. He proposed a vote of thanks to Mr. 

 Suffolk, which was unanimously parsed. 



A paper by Dr. Maddox, "On the Structure of Lepidopterous 

 Scales, as bearing on the Structure of Lepidocyrtus curvicollis" was 

 then read. 



Mr. Slack said, if Dr. Maddqx had found the pigment in the scales 



