18 Ouertes. 
stirring or shaking. While hot, it is poured on metal plates to 
cool. Before using, it requires to be liquified by heat, and quickly 
applied with a brush, as it soon hardens. 
Gold Varnish for Frames.—Take of turmeric and gamboge, 
ofeach 1 drachm; spirit of turpentine 2 pints; shellac and sand- 
arach, of each 5 ounces; dragon’s blood, 7 drachms; thin mastic 
varnish, 8 ounces. Digest with occasional agitation for fourteen 
days in a warm place, then set aside to fine, and clear off the pure 
liquid. ‘This is to be applied on the frames previously silvered. 
Queries. 
All Questions and Answers should be clearly and concisely written on one side 
of the paper only, and every question or answer must bear the name and address 
of the writer. If this is written on the left-hand bottom corner, it will not be 
published, in which case initials or other signature should appear in the usual place. 
When more than one question is sent by the same correspondent, each must be 
written on a separate piece of paper. 
Correspondents, in sending us answers to questions, are desired to commence 
by quoting the number and title of the question as printed, before beginning their 
reply. All answers should reach us before the r2th of the month. 
317.—-Styrax.—What are the advantages of mounting in liquid 
styrax ? MUA: 
318.—Fish Skin and Scales.—What is the best way to mount 
the skin and scales of fish to show to the best advantage with or 
without polariscope ? i. 
319.—Sections of Teeth and Bone.—What is a good medium to 
mount hard sections, such as bone, teeth and horn, one in which 
they will not change, or their minute structure will not be lost ; 
that is lacunze, canaticuli, and dentinal tubules, etc.? Balsam 
obliterates and glycerine has a solvent action on the lime salts. 
A.B. 
320.—Arranged Diatoms.—What is the best size for holding 
diatoms in arranged slides ? STELLA. 
321.—Cleaning Diatoms.-——What is the best method of elimina- 
ting flocculent matter from diatoms after boiling ? DiaTom. 
322.—Bleaching Diatoms.—What is the best bleacher for 
diatoms to be used when boiling ? DIATOM. 
323.—Barbados Earth.—Will any reader give the best and 
easiest method for breaking down Barbados earth before boiling ? 
S. 
324.—Rusty Pork and Bacon.—Will some one tell me the 
cause of bacon and pork turning rusty, and how to prevent it? I 
should also be glad to know what the “rust” is; is it a chemical 
change in the meat, or is it caused by a fungus ? PRG: 
