THE MICROSCOPE. 139 
MICROSCOPICAL LABORATORY NOTES.* 
H, M. WHELPLEY, PH. G., F. R. M.S, 
ISSECTING KNIVES.—The delicate blades of small dissect- 
ing knives are liable to become injured if the instruments are 
not carefully cared for when not in use. I find that a small piece 
of thick blotting paper can be slipped over the blade like a sheath to 
asword. If the blade is dipped in vaselin before putting it away 
there is no danger from rust. 
Gonp Sizz.—The works on microscopy give complicated and 
tedious methods for making gold size from linseed oil (olewm lint). 
It is entirely unnecessary to follow them, as the article can be pur- 
chased from varnish dealers at fifty cents per pint. It is known as 
“gold size varnish.” It costs more than this to make it by boiling 
linseed oil with litharge, or passing oxygen through the oil, as one 
ingenious writer suggests. Gold size can be used as a cement as it 
is, but I prefer to add about one-fourth the bulk of benzol to thin it, 
so that it flows more smoothly from the brush. 
A VauuasiLe Lamp.—TI have tried numerous kinds of lamps to 
find the one most suitable for general use. The most serviceable one 
seems to be a Pinnefore burner and chimney on a large bracket 
bowl that is supplied with a handle and an opening for filling the 
lamp. When arranged with a large white shade the outfit costs but 
$1.15 and is much more useful than the expensive student’s lamps, 
or special ones made for microscopists. If the light is too low for — 
some work it can be easily raised by placing the lamp on a cigar box 
or blocks of wood. 
Brunswick Brack—Of late this cement has been made by 
replacing the oil of turpentine with benzol, which makes a smoother 
cement and causes it to dry more quickly. It also makes it much 
more expensive. I find that the rectified oil of turpentine answers 
nearly the same purpose as the benzo] and is not so expensive. It 
is also necessary to use the true Trinidad asphaltum, and not the 
ordinary kind that is made into street pavements. I make the cement 
by dissolving Trinidad asphaltum in rectified oil of turpentine until 
of the proper consistency and then straining through muslin. To 
this add nut oil in the proportion of five minims to the fluid ounce 
of cement. 
Do Nor Waste Atconor.—The alcohol used in washing sections, 
and many other operations, should not be thrown away, but placed 
* Read before the St. Louis Club of Microscopists at the February meeting. 
