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POPULAR SCIENCE REVIEW. 
temperature is employed lime crucibles are used, but there is much diffi- 
culty in preparing them, and when made they are often broken. One of the 
great difficulties in the way is that of obtaining blocks of lime of a sufficient 
size for scooping out a crucible, most large blocks being cracked. Clay 
crucibles lined with lime have been tried, but they too have failed, being 
often melted themselves. Under these circumstances the following method, 
suggested by Mr. D. Forbes, F.R.S., appears to be a good one. A clay 
crucible, of somewhat larger capacity than the desired lime one, is filled 
with common lamp-black, compressing the same by stamping it well down. 
The centre is then cut out with a knife until a mere shell or lining of lamp- 
black is left firmly adherent to the sides of the crucible, and about half an 
inch or less in thickness, according to the size of the crucible ; this lining is 
now well rubbed down with a thick glass rod until its surface takes a fine 
glaze or polish, and the whole cavity is then filled up with finely-powdered 
caustic lime and pressed down as before, and a central cavity cut out as 
before, or the lime powder may be at once rammed down round a central 
core of the dimensions of the intended lime crucible. The lime lining is 
soft before it is placed in the furnace, but it soon agglutinates, and forms a 
compact crucible, which is prevented acting on the outer one by the inter- 
mediate stratum of lamp-black. This crucible will stand the heat of melted 
wrought iron or cobalt without fusing or cracking. — Vide Chemical News , 
January 4. 
A Mineral of Yttria in the Alps . — In the Annalen der Chemie Herr W artha 
describes, under the title of Wiserine, an Yttriferous mineral which has 
been found in the Haut-Valaise. It crystallises in square-based prisms 
similar to zircon. It was supposed to contain silica and titanic acid, but 
M. Wartha has found this to be an error, and that, excepting a little iron, it 
contains only phosphoric acid and yttria. It is a phosphate of yttria, iden- 
tical with the xenotime of Berzelius. 
THE MEDICAL SCIENCES. 
The Structure of Muscle. — In a late No. of Siebold and Kolliker’s Zdt- 
schrift , Professor Kolliker publishes a paper on the subject of the compart- 
ments seen in transverse sections of muscle. These were described some 
years since by Herr Cohnheim, whose views have now been corroborated 
by Herr Kolliker. In the present paper, the author concludes that the 
muscles are really composed of fasciculi, and that the material which binds 
the fibres together is different from that which unites what Mr. Bowman has 
styled the sarcous elements. 
Distribution of the Rods and Cones in the Retina of Mammalia. — In the last 
No. of the Microscopical Journal there is a very able translation and con- 
densation of Herr Schultze’s recent memoir on the retina. Those who are 
interested in the comparative anatomy of the retina should read this paper 
attentively. It is full of interesting details, and, among other matters, -it 
gives an account of the distribution of the rods and cones of the retina in 
