THE MICROSCOPE. 7 
that of the published formulas. The following seems to be the 
thing sought: 
(ClyeGigiteh nn cobddsdatdcpossorBepDceocee’ 20 parts. 
NIGH Strihest sy saiet cesta epasea/o¥ave! cciaral ey sey ells okavel s 8 a 
PASTIME) Os sab aracaletars BielaTtl x sees sla are ews s. Sre ale 2a 
Carpolicracid mrt cok! asc aeila-diste Weisel Sais « ak Di 
A little variation in the quantities is not important; but the 
glycerine must not be much less, more may be used. The fuchsin 
is the common aniline-red of the shops, called also magenta. Mix 
all together and shake or stir well. This mixture may be kept in 
stock and no deterioration occurs as is usual with the alcoholic ones 
after a few weeks. 
When ready to use the stain put two or three drops into a watch 
glass (or other dish) full of water and stir. Occasionally precipita- 
tion suddenly occurs if the stirring is at first too violent, but when 
once dissolved nothing of this kind happens, for it is the water 
which evaporates if anything, not the glycerine, which, like alcohol, 
is the stronger solvent of the coloring material and the oil. The 
color now should be a very light cherry-red, much too diffuse for 
writing ink and so that touched to the hand and wiped. off scarcely 
a trace remains. In this the sputum on cover-glass may be placed 
to remain from ten minutes to several days at the ordinary tempera- 
ture of an occupied room, but the best results are obtained by heat- 
ing from 80° to 100° Fahr., and for a fourth to a half hour. But if 
quicker, though for permanent mounts less satisfactory, results are 
desired, boil a little water in a test-tube and at once add about 
double the quantity before suggested of the stain by letting it run 
down the tube held a little obliquely and gently shake. Now pour 
the hot liquid into an open-mouthed dish and immerse the coated 
cover-glass one to two minutes without further attention to the tem- 
perature; decolorize and examine. 
By these methods with this material there have been no failures 
in many trials, no vexatious precipitations mar the results, and 
everything is easily cleaned up, whether done immediately or at 
- one’s convenience afterward. 
Spread the sputum thinly on a cover-glass, heat in a flame until 
nearly scorched, stain, put into nitric (or hydrochloric) acid and 
water, one part to four or more, until decolorized, say one minute, 
wash in water and examine; or if desired stain the ground material 
