36 Answers to Queries. 
in benzole is placed round the cover. This soon hardens and 
maybe finished with zinc cement. ‘The starch does not stain, but 
is surrounded. V. A. LATHAM. 
Answers to Queries. 
317.—Styrax.—According to A. C. Cole, styrax is a perfect 
substitute for balsam, and its solution easier to work with and 
more permanent and durable. The /ournal of the Royal Muicro- 
scopical Society, June, 1884, gives the refractive index of styrax as 
1°585, showing a considerable advantage over balsam. A. N. T. 
317.--Styrax.—I much prefer Styrax to any other medium, 
especially when mounting diatoms. I have made a series of 
experiments with some sixteen other media, but none have proved 
so satisfactory for cleanliness and clearness of resolution. A. W. G. 
320.—To Arrange Diatoms.—In arranging Diatomacez for the 
microscope, the slide should first be dusted with gum finely 
powdered, and as the diatoms are arranged, by gently breathing 
on the slide they will become fixed. V. A. LatHaM, 
320, 321, 322.—Diatoms.— Your correspondents would do well 
to procure copies of the /ournal of Microscopy for July and 
October, 1884, containing papers by Mr. Griffin, on the “ Collection 
and Preparation of the Diatomace.” 5. bi 
321—Arranged Diatoms.—Diatoms may be arranged in lines 
or patterns in two or three ways; one of which is that a thin 
solution of isinglass is made in hot water, and lightly brushed over 
the centre of the slide, and when nearly dry the Diatoms are 
arranged upon it, according to desire; the cover-glass is placed 
upon it, and a drop of Canada Balsam in Benzole, or Styrax in 
Chloroform is placed on the outer edge, when the air is displaced 
by the incoming fluid, and the isinglass also dissolved away. 
When, however, the finer varieties of Diatoms are required as test 
objects, it is well to mount them directly upon the glass cover. 
Geisbricht’s method is as follows:—The slide is coated with a 
solution of shellac in absolute alcohol, washing over this with oil 
of cloves, and when the Diatoms are arranged in patterns, warm 
the slide, and the oil of cloves is soon evaporated, leaving only 
the work to be done of putting on the cover-glass, and the filling 
in with either of the two mentioned media. A WG 
mn et 
LE 
