SCIENTIFIC SUMMARY. 
251 
is then pulled out from the bottom of the case, is fixed by means of a catch, 
like a house-ladder, and the apparatus is ready for use. Alteration of focus 
is obtained by an easy telescopic movement, and as the universal screw 
is employed, any objectives may be used. We have used Mr. Moginie’s 
microscope, and can speak well of it. It is a handy instrument, and will be 
found useful by hospital physicians and field botanists. 
The ^th Objective used with the Binocular Microscope. — We understand 
that by an arrangement of prisms and parallel plates Messrs. Powel & Lealand 
have succeeded in obtaining perfect definition with a T l 5 th inch object- 
glass employed with a binocular microscope. 
Papers relating to Microscopic Anatomy : — 
• Botany. 
The Proper Vessels of the Aroidese. 
The Fibre-cells of the Anther. 
The Structure of the Partitions of the Anthen. 
The Parts involved in the Process of Defoliation. 
Geology. 
The Structure and Affinities of Eozoon. 
Medical Sciences. 
Who first discovered Trichina ? 
The Production of Cholera. 
The Organization of the Cell. 
The Structure of the Blood Globules. 
Zoology. 
Structure of the Investing Tunic in Gregarinidse. 
The Development of the Infusoria. 
The Metamorphoses of Ostracoda. 
MINING, METALLURGY, AND MINERALOGY. 
W elsh Gold. — During the year 1864 we learn, from statistics only recently 
published, there were five gold-mines working in Merionethshire. In these 
2,336 tons were crushed, from which 2,887 oz. of gold, valued at £9,991, were 
obtained. This is in excess of the quantity obtained in 1863, which was 
only 552 oz. ; but it is considerably less than the production of 1862, when 
5,299 oz., having a value of £20,390, were extracted. 
Improvement in Pattison’s Process for Separating Lead from Silver. — An 
account of an improvement of this kind appears in the Bulletin de la Socieie 
Chimique for January. In a factory at Roltzappel they melt the lead in a 
pot, and then run it into a crystallizing pan, when they cover the surface with 
small fragments of coke, upon which a thin stream of water is directed. An 
agitator being set in movement, a circular motion is given to the mass of 
metal covered with coke, and thus the entire surface is equally moistened 
and cooled by the stream of water. In about an hour the lead loses its 
fluidity, and forms a solid crust, which envelops the small pieces of coke. The 
stream of water is now turned off, the agitator is stopped, and the unsolidified 
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