136 On the Structure of Rice Paper. 



parts of the film. As the olive oil had now taken the place 

 of the air, and filled all the cells, the film beame perfectly 

 transparent, and displayed its vesicular structure when plac- 

 ed under a powerful microscope. 



It will appear from the drawing executed by Mr. Greviile, 

 Plate II. Fig. 11, that the rice paper consists of long hex- 

 agonal cells, whose length is parallel to the surface of the 

 film ; that these cells are Jilted with air, when the film is in 

 its usual state ; and that from this circumstance it derives 

 that peculiar softness which renders it so well adapted for the 

 purposes to which it is applied. When the film is exposed 

 to polarised light, the longitudinal septa of the cells depolarise 

 the light like other vegetable membranes. 



Among the three specimens of rice paper which I have 

 produced, there is one from which all the air has been expell- 

 ed by the boiling oil ; another in which some of the air bub- 

 bles still appear in the vesicles, the air having been only par- 

 tially expelled by boiling water; and a third, which is in con- 

 tact with water, without having been deprived of any of its 

 air bubbles. 



Upon mentioning to Mr. Neill the preceding experiments, 

 he informed me that the lady in Edinburgh, Miss Jack, who 

 had employed rice paper with such success in the manufac- 

 ture of artificial flowers, had learned from her brother, who 

 was in China, that it was a membrane of the bread fruit tree, 

 the arlocarpits incisifolia of naturalists. 



No. IV. On the Convergence/ of the Solar Beams to a point 

 opposite to the Sun. 



The divergency of the solar beams, when the sun is de- 

 scending in the west, is a phenomenon which occurs so fre- 

 quently, that the most careless observer must have had occa- 

 sion to notice it. This phenomenon, however, is sometimes 

 accompanied with one of an opposite kind, viz. the conver- 

 gence of the solar beams to a point opposite to the sun, and as 

 Jar below the horizon as the sun is above it. This phenome- 

 non is extremely rare ; and we are not aware that it has been 

 described more than once, viz. by Dr. Robert Smith of Cam- 



