232 



THE AMEEICAN MONTHLY 



[December, 



should also be used, and their advan- 

 tages and disadvantages demon- 

 strated. 



I take it for granted we have 

 learned something of illumination, 

 and the use of achromatic and mono- 

 chromatic light. So, without further 

 parley, we take up the blood as the 

 first subject for investigation : first, 

 frog's blood, then human. We study 

 its anatomy in the passive state, and 

 are left to imagine what relation the 

 different corpuscles hold to each 

 other while circulating. The circula- 

 tion, as seen in the bat's wing, frog's 

 foot, or the gills of the salamander, is 

 something which every medical man 

 should not only look at but study ; 

 and, having thoroughly studied it in 

 its normal state, he should follow it 

 through the different stages of inflam- 

 mation. Blood-crystals come next 

 in our course. The dry blood pro- 

 cess is used generally, and we obtain 

 some fair crystals. The wet processes 

 are usually ignored, and foolishly, too, 

 for by their means we obtain the 

 most perfect specimens. The medico- 

 legal branch of the subject is rarely 

 touched upon. Then, without teach- 

 ing the mode of permanently preserv- 

 ing the blood-corpuscles and crys- 

 tals in wet or dry mounts, we are 

 led on to connective tissues and 

 the epitheliums. A little staining in 

 carmine is now done, and we begin to 

 feel we are doing something. We 

 tease out muscular and other tissues, 

 and really begin to cut sections — that 

 is, to chip off wedges. The hardening 

 of the tissues does not concern us 

 particularly — it is enough for us to 

 know they were once soft, now hard, 

 and since hard we have the privilege 

 of purchasing a fine set of dissecting 

 instruments, and a Valentine or other 

 knife for section cutting. Why are not 

 laboratories furnished with all the 

 tools necessary to accomplish the de- 

 sired purpose ? Teach the students 

 what good tools are, so they can 

 choose such when they purchase. 

 Such a thing as a microtome is 

 seldom thought of, still less frequently 



seen. A very ingeniously cut and 

 folded piece of writing paper, con- 

 verted into a box, receives the speci- 

 men and embedding material, and 

 serves as the microtome. The micro- 

 meter screw is your eye, plus a deli- 

 cately trained hand and arm. As a 

 result, the majority of men go out 

 from our colleges incapable of cutting 

 a transparent, even section, and never 

 dreaming of such a thing as a micro- 

 tome. We must not neglect the freez- 

 ing microtome, even if to see it in the 

 demonstrator's hands is the nearest 

 we can approach it, we will have that 

 much to be thankful for. After 

 running hastily through the urinary 

 deposits our course ends. 



Turn-tables and the host of finish- 

 ing cements are foreign to the " prac- 

 tical " laboratories. Balsam and da- 

 mar are the mounting media and 

 finishing cements. Turn-tables for 

 centering objects are a superfluity, 

 simply because an object mounted 

 out of centre is in all respects equal 

 to an object mounted in centre. And 

 suppose the edges of the cover 

 have not been cleaned of the balsam 

 — suppose they do look smeared. 

 That does not affect the value of the 

 preparation beneath the cover. Such 

 is the laboratory talk ; and it may be 

 true to a certain extent. But the con- 

 verse is equally true — the decentered 

 object and smear do not enhance its 

 value, while a neat finish to a cen- 

 trally mounted object is, to say the 

 least, pleasing to the eye. 



The exchanging of slides has be- 

 come so common a practice among 

 microscopists that almost every work- 

 er has specimens of almost every 

 other one's work. Run over the cabi- 

 net of one who has done much ex- 

 changing, and what do we find ? One 

 thing particularly, viz. : that almost 

 all the badly cut and mounted speci- 

 mens have physician's names on their 

 labels. Few glorious exceptions there 

 are, but upon inquiry we find that 

 none of these received their know- 

 ledge from their alma mater. 



The dissecting microscope is an- 



