1902} MICROSCOPICAL JOURNAL. ~ 87 
atin freshly prepared. He dissolved the paraffin with tur- 
pentine, stained with carbol-fuchsin, washed with alco- 
hol, 50 per cent and move up to absolute, soaked in xylol 
and mounted in C. Balsam. The vessels and parenchyma 
alone were affected by P. campestris. The short bacteri- 
um infesting many bundles and cavities in the parenchy- 
ma were found. This method of fixing and handling al- 
lows a complete study of the organism. The knife does 
not displace or tear the material, All stages in the des- 
truction of cell walls are exhibited, from single cells to 
large cavities filled with debris and P. campestris. It 
crowds the cells apart, breaks down the middle lamella 
and then gradually obliterates the cell walls. 
LUSTRELESS BLACK VARNISH FOR OPTICAL INSTRU- 
MENTs.—Rub fine lampblack with shellac varnish. If 
the surface of the varnish when dry shows any luster, it 
contains too much shellac and should be diluted with al- 
cohol. It is said that this isa safer varnish to use in pho- 
tographic dark slides than any kind containing turpentine. 
CoNnvENTION.—The American Congress of Tuberculosis 
meets in New York, May 14, 15 and 16 at Hotel Majestic. 
An effort is being made to present a collection of objects 
including microscopical and biological in connection there- 
with. Slides can be sentto Dr. H, Edwin Lewis at Bur- 
lington, Vt. up to the week of the convention. 
-Liguip GLuE.—lIn a solution of borax in water, soak a 
good quality of glue until it has thoroughly imbibed the 
- liquid, Pour off the surplus solution and then put on the 
water bath and melt the glue. Let it cool down until the 
glue begins to set, then add, drop by drop, with agitation, 
enough acetic acid to check the tendency to solidification. 
If after becoming quite cold there is still a tendency to, 
solidification, add a few drops more of the acid. The 
liquid should be of the consistency of ordinary mucilage 
at all times, 
