THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL 



Vol. XL DECEMBER, 1890. No. 12. 



All c ovimunic alio Jis for this Joiinial, whether relating to business or to editorial 

 matters, and all books, pamphlets, exchanges, etc., should be addressed to Ameri- 

 can Monthly Microscopical Joiiriial, Washington, D. C. 



European subscriptions may be sent directly to the above address accompaniea 

 by Inter7iational Postal Order for Si. is p(^f^ annum, or they may be sent to Messrs. 

 Triibner &^ Co., 57 Ludgate Hill, London, or to Mr. IV. P. Collijis, /j/ Great 

 Portland street, London, accompanied by the yearly price of five shilli?igs. 



Microscopy for Amateurs. 



By T. charters WHITE, 



QUEKETT CyjB. 



{^Continued from page 2^4-'] 



Section Cutting. — Probably the first desire, which is also more 

 easily gratified, is that of being able to make sections. Tissues to be 

 reduced to sections come under two heads — hard and soft. As each 

 requires a different treatment, it must be dealt with separately ; sections 

 of hard tissues being more readily accomplished, command first atten- 

 tion. The hard tissues comprise such substances as bone, teeth, woody 

 shells, like cocoanut shells, the various hard woods, and the stems of 

 plants. There are two methods by which sections of osseous tissues 

 may be obtained ; they may be made by sawing oft thin slices and grind- 

 ing them down to the requisite thinness, or they may be soaked for 

 several days in weak acid and water until the lime is dissolved out, 

 when thin sections may be cut with a razor. The former method may 

 be adopted, not only from its simplicity, but because it gives a more 

 correct insight into the histological characters of the bone than is af- 

 forded by the softened and dislocated elements of a decalcified section. 



Grinding' down Sections of Bone and Teeth. — The piece of 

 bone to be cut having been freed from grease in a solution of common 

 washing soda, is cut into slices with a watch-spring saw ; in this condi- 

 tion the slice is too thick, and little or nothing of its histological struct- 

 ure can be seen. It may be rubbed down between two plates of ground 

 glass, with the addition of some pumice powder and water, when, by 

 grinding one plate upon the other, the slice of bone between them gets 

 gradually thinner, till, unless the process is continued with great care 

 and frequent examination, the section disappears altogether ; as the 

 pieces of ground glass get rubbed smoother by use, it is better, in order 

 to avoid such a mishap, to change the section to older and worn ground 

 glass. It will not be ground down so quickly at this stage, and will be 



Copyright, 1890, by C. W. Smiley. 



