ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 577 



orange-yellow. In a section (transverse) of the leaf-stem of the 

 sago-palm, the outer cells, which are smaller and more compact than 

 the more central ones, were dyed a rich orange-yellow, and their 

 nuclei a bright carmine. The curious large ducts in the central 

 portion of the stem, which, as a system, form in a transverse section 

 a figure like the Greek capital omega, take a pleasing variety of 

 shades, the cells around the edges being a bright orange, the central 

 cells shading down to deep carmine. These sections of the midrib of 

 the sago-palm are beautiful objects stained or unstained, and one of 

 the best examples of curious cell arrangements to be found anywhere. 

 The action of the dyes made from the above formula is quick and 

 certain, and the effects very satisfactory. 



Cutting Sections of Coal.*— Some discussion has taken place as 

 to the feasibility of the method mentioned in the ' Micrographic 

 Dictionary,' of macerating the coal in a solution of carbonate of 

 potash, several authors finding that the coal still remained quite hard 

 and impossible to cut. C. L. Lord finds the following method to be 

 easy and successful when tried on the particular kind of coal men- 

 tioned by Huxley as containing macrospores and microspores in such 

 abundance, viz. the Better-bed coal of Bradford and district. Grind 

 a chip of coal to a smooth surface on an ordinary school-slate. Then 

 cement it to a glass slide, either with shellac or Canada balsam. If 

 balsam is used, it must be evaporated until it is of such hardness that 

 a dent can only just be made in it by pressure with the thumb-nail, 

 then remelt it and fix the smooth surface of the coal to the slide. 

 The coal may then be ground on the slate to such a thinness as to 

 show the spores. The coal-matrix containing the spores cannot be 

 ground sufficiently thin to be transparent, and if it could be so 

 ground, it is doubtful whether there would be any organic structure 

 perceivable. 



J. Walker selects from soft Iowa coal, some hard heads, so called 

 (that is, hard lumps of coal in various stages of transition from good 

 coal to charcoal), and well-preserved wood mixed with sulphide of 

 iron. Breaking up these lumps and cutting out with a chisel the 

 wood from the coal, which is the same as the coal without the 

 bitumen, and breaking this in the proper direction, sections can be 

 got both ways of the tissue, and when ground down thin make a good 

 transparent object, or opaque with the condenser, when the sulphide 

 of iron glistens like gold-dust among the woody tissue. 



W. H. Harris has tried repeatedly to get a good slide of ordinary 

 coal, and the outcome is one section only that shows any structure, 

 and this was cut from ordinary marketable coal from Illinois, U.S.A. 

 A piece of the coal was cut about a quarter of an inch in thickness 

 with a fret saw, placed in pure turpentine for some considerable time, 

 and then in dilute Canada balsam, until it was saturated. The 

 turpentine was allowed to evaporate, and by a gentle application of 

 heat the balsam the section had absorbed was gradually hardened. 

 One side was then ground flat, polished and cemented to the slide ; 



* Sri -Gossip, 18S2, pp. 89, 13G-7. 

 Ser. 2.— Vol. II. 2 Q 



