218 



HARDWICKE'S SCIEN CE -GO S SIP. 



few days after my discovery, a second visit to the 

 quarry, but, by the removal of the stone, all trace 

 beyond my sketch of the spot was lost. I found in 

 its immediate vicinity abundance of stems of cala- 

 mites, but no trace of Lepidodendroid plants ; but 

 when conversing with the quarrymen, they told me 

 that the " scaly specimens " were scarce, but that 

 near to this spot they found a few during the month 

 previously to my first visit. 



From the position of the stems, and also of the 

 " spores," I inferred at the time that these must 

 have been drifted from some carboniferous forest to 

 the west of these beds. I will draw the attention 

 of your readers to H. C. Sorby's paper in the 

 " Quarterly Journal of the Geological Society," and 

 also your own extract from that paper in Science- 

 Gossip.* The fossil forest in the coal measures 

 described by him is directly west of Wincobank 

 Hill, and being well acquainted with both places, I 

 am satisfied that the current which drifted the waste 

 wood, &c, into Wincobank Hill district flowed 

 from the west. 



Attercliffe, Sheffield. G. 11. Vine. 



SECTION AND SECTION CUTTING. 



TTAVING read with much interest Mrs. Merri- 

 -*■-*- field's remarks on cutting sections of algae, 

 it occurs to me that a few notes on cutting sections 

 of vegetable structures in general 

 may prove not uninteresting to some 

 of your readers. 



Mrs. Merrifieid must, I think, have 

 been unfortunate in her experience of 

 section machines if she discarded them 

 for the more primitive method de- 

 scribed in her paper, inasmuch as I 

 have fouud the machine advertised 

 in this journal as the " Science- 

 Gossip Section Machine " all that 

 can be desired, and the price (7s. Cd.) 

 is very reasonable. 



The needful appliances for all ordinary sections 

 are : — 



A " Science-Gossip " or other section machine. 



A keen-edged razor. 



Sundry slips of glass, 3 in. by 1 in., and their 



glass covers, either round or square. 

 A pair of needles set in wooden handles (those 



used for camel-hair pencils will do). 

 A couple of small china saucers (those supplied 



in the cheaper descriptions of paint-boxes 



are, perhaps, best). 

 A camel-hair pencil. 

 A carrot. 



* No. 128, p. 1S8. 



The Science-Gossip machine, to which I give 

 preference, as I am much better acquainted with it 

 than with any other, consists of two long narrow 

 inclined planes of nearly equal inclination, some 

 12 or 14 inches in length, the upper sliding in a 

 groove in the lower. Over the middle is a small 

 bridge of wood faced at the top with a level plate 

 of brass, and pierced with a cylindrical hole about 

 f in. in diameter. In this hole is a piston, the rod 

 of which rests on the upper plane. The object 

 of which it is desired to cut a section is placed 

 in the hole on the piston. It is evident that, if 

 one plane be slid over the other, it will urge 

 the piston upwards ; but, as the inclination of 

 the planes is nearly equal, the vertical motion will 

 be very small as compared with the horizontal 

 motion. 



The mode of use will be best explained by an 

 example. Suppose we desire to obtain a transverse 

 section of a leaf. Draw out the two planes to 

 almost their fullest extent ; press down the piston 

 till its rod is resting on the upper plane. A piece 

 of hard wood is usually interposed to prevent 

 injury to the plane. Next, cut a piece of carrot to 

 fit the hole stiffly and come, when resting 'on the 

 piston, nearly level with the brass top of the bridge. 

 Now cut the carrot nearly through vertically ; place 

 the leaf to be cut between the two halves, which, 

 when, placed in the hole, will support it firmly. 

 Having fixed it in the hole, with a razor, thoroughly 



Fig. 151. " Sciknce-Gossip Section Machine."— A B, C D, two inclined planes 

 of nearly the same inclination, C D sliding: over A B ; E F, bridge faced with 

 brass, and pierced with a cylindrical hole, G, in which is a plunger, which 

 urges upwards the object to be cut, which is placed in it supported by pith, 

 carrot, &c, when C D is moved in the direction of the arrow. A small 

 piece of hard wood is placed between the rod of the plunger and the plane, 

 CD, to prevent injury to the latter. 



wet, cut the carrot and contained leaf exactly level 

 with the brass ; then push forward the upper plane 

 say g in., and make a second cut level with the 

 brass, This will give you a very thin slice of the 

 carrot and of the leaf along with it. With the 

 mounted needles carefully push the slice altogether 

 into the little saucer previously filled with water ; 

 move it about a little, when it will part from the 

 leaf, which may be picked up on the point of a 

 needle, or with the camel-hair brush if it be very 

 delicate, and placed on a glass slip in a drop of 

 water. Cover with a bit of thin glass, and place 

 under the microscope. In this way, with a little 

 practice, it will be found that the only limit to the 

 thinness of the section is the sharpness of the 

 razor ; a thickness of only ^ v or -^ is readily 



