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RULES FOR PRESERVING,, ETC. 



HOW TO MAKE SECTIONS OF ALG^ FOE 

 MICEOSCOPIC EXAMINATION. 



For making sections or durcJiscJinitts it is necessary to have a small working micro- 

 scope, a few glass slides and thin cell-covers, and a delicately fine knife. 



An excellent microscope of the proper sort is to be had for a few shillings; and 

 if the knife it contains be not sufficiently fine, an infant's gum lancet, well sharpened, 

 answers the purpose. 



The little instrument has, of course, a stem on which the eye-glass runs up and 

 down; and this being fastened to the wood- work of the box, can be shut in or turned 

 out at will. When turned out, the box itself forms a small stage or platform to work 

 upon; the student looking down upon it through the glass. Note here, that it is well 

 to gum a piece of white paper on the stage to begin with, as the operations to be 

 performed are thus more easily seen. On this stage place a glass slide, and on the slide 

 place a morsel of the plant to be examined, say a quarter of an inch or so of a stem or 

 branch. Hold this scrap firmly down to the slide by the first finger of your left hand, 

 pressing the nail against its extreme end, so that as you look through the eye-glass you 

 can only see the merest edge of the plant. Then, with the knife or lancet in your right 

 hand, slice ofi" this mere edge (the thinner the slice the better), and drawing the left nail 

 very slightly back, leave another mere edge, which cut off in a similar way; and so 

 another, and another, and another, till you have six or eight slices on your slide. 



Now wet the tip of a finger in clean water, and let down one small drop thereof upon 

 the centre of the slide; into which minute pool coax your little durcTischnitts, by the aid 

 of the small pointer contained in your microscope box, and then — replacing the slide on 

 the stage — give yourself the pleasure of watching the magnified slices expand in the 

 liquid. 



With fresh-gathered plants there is no difficulty, of course, but sections of dried 

 specimens are occasionally troublesome, by refusing to resume their natural shape. 

 A drop of muriatic acid will sometimes induce them to open, but not always. 

 Nevertheless, it is so rarely possible to mend the matter by moistening the dried 

 specimen hefore it is cut, and clean, good sections are so much more easily made 

 of dried plants than of re-moistened ones, that the rule is, to cut them in their 

 dried state, as a first eff'ort, and resort to other expedients, if necessary, afterwards. 



But to proceed. The sections being more less expanded, take one of the thin 

 cell-covers (ascertaining that it is clean and bright), and let it gently down upon 

 the slide over the little pool and its contents, and you have at once a microscopic 

 slide ready for examination under your compound microscope. 



Troublesome as this operation may seem to be, when read of, it is a very amusing 

 one in practice, and by no means hard of accomplishment. Longitudinal sections 

 are made in the same way; but it is always well then to secure a fork in the 



