232 C. Johnston on Microscopical Preparations. 
nized as identical with turquois by these travellers, it is possible 
that they neglected to give the Mexican name. It is also possi- _ 
ble that this name originated in Mexico and not among the tribes 
near the locality, although it is now in use there. It is desirable 
that this ancient name should be retained and I suggest that this 
New Mexican variety of turquois may be appropriately known 
among mineralogists as chalchihuztl, 
ee 
Art. XXII.—On a method of Preparing and Mounting Hard 
Tissues for the Microscope ; by CHRISTOPHER JonNSTON, M.D. 
and certain method of preparing and mounting hard tissues, such 
as bone, teeth, shells, fossilized wood, &c. ‘ 
I am aware that treatises upon the microscope give a few in- 
dications for making sections and embalming them in Canada 
Isam; but they are unsatisfactory either by reason of theif 
brevity or their want of precision. Specimens may be procur ed 
ready-made from the hands of Topping, Bourgogne and others, 
but while they are expensive, persons in remote situations are 
obliged to purchase by catalogue without the opportunity of se 
lection. Besides, it is oftentimes difficult or else impossible to 
obtain series of particular objects; so that the student must 
either limit his researches or “prepare” for himself: im the ee 
er case he may increase his number of objects indefinitely, ad 
supply himself with many such as are not attainable from abroad, 
and divided in any direction he may require. ; 
microscopic section should be as thin as the structure i 
the object will allow, of uniform thickness, and polished on Oe 
sides, whether it be mounted in the dry way or in balsam. ? 
meet these requirements I proceed as follows :— 
pei | provided wi 
t Pe 
A coarse and a fine Kansas hone, kept dressed flat with 
fine emery ; 
2. A long fine Stub’s dentist’s file; 
3. A thin dividing file and fine saw; : ‘th 
4. Some Russian isinglass boiled, strained, and mixed Wl 
aleohol sufficient to form a tolerably thick jelly when cold ; 
5. A small quantity of Canada balsam ; 
6. Slides; 7. Cover glass; tas 
8. One ounce of chloroform; 9. One of F.F. aqua ammonia; 
~ 10. Some acaaganie of thick plate (mirror) glass 1 inch square 
finall 
orl by 2 inches; an y> 
ic el cl 
Be eee 
les 
