ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 777 



Bottle for Immersion Oil.* — A. Schuberg describes a bottle for 

 immersion oil made by W. and H. Seibert of Wetzlar. The neck of 

 the bottle is prolonged upwards into a funnel-shaped expansion, the 

 diameter of which equals that of the bottle itself. The outer edge of 

 this expansion is ground for the reception of a bell-shaped glass capsule. 

 The glass stopper is prolonged downwards into a thin rod, nearly 

 reaching the bottom of the bottle, and ending in a small pear-shaped 

 head. The stopper possesses three deep vertical grooves which permit 

 any excess of oil to run back into the bottle. The advantages claimed 

 are : the oil can be removed without the bottle becoming smeared, 

 and soiling of the grip of the glass rod, etc. is avoided ; the quantity 

 used can be easily regulated ; all parts can be easily cleaned ; and the 

 bottle can be carried about full. 



A Modification of the Pantograph for the Drawing of Micro- 

 scopical Preparations.! — F. V. Friedlander has designed a modifica- 

 tion of this instrument, in which the angle of the parallelogram, carrying 

 the guiding-pin, is not, as in the stork's-bill, a solid vertical axis, but is a 

 ring-joint of the two limbs of the parallelogram which here meet. This 

 ring is 44 mm. in diameter, and its centre corresponds to what 

 would have been the crossing of the two limbs. It is thus possible to 

 view from above the preparation to be drawn. The guiding pin 

 which follows the contour of the preparation, passes obliquely down- 

 wards from one of the limbs of the parallelogram to its position under 

 the ring. Its position can be altered and fixed with a screw, to suit 

 objects of different thickness ; the point, however, is always directly under 

 the centre of the ring. The ring is adapted for the reception of a 

 drawing Microscope. The whole apparatus is fixed with a screw 

 to a drawing board, which, for the use of transmitted light with the 

 Microscope, has a piece cut out and covered with glass. The apparatus 

 gives an enlargement of 2-10 diam. The right hand guides the 

 drawing point, while the eye, from above, controls the movement of the 

 guiding point on the preparation. 



Metallography, &c. 



Micrographic Study of Cast Iron.! — The distribution of the 

 impurities in cast iron offers many features of interest to the engineer. 

 P. Longmuir has briefly examined some typical cast iron, and repro- 

 duces their characteristic structures. He gives a few notes on heat 

 treatment for the production of "black heart " and malleable cast iron. 



Note on the Amphibole Hudsonite previously called a Pyroxene. § 

 S. Weidman having made thin sections of hudsonite and placed them 

 under the Microscope, it was seen by the prismatic cleavage of 56° 

 and 124° and by the optical properties of low birefringence, strong 

 pleochroism and absorption, that this mineral is an amphibole, and not 



* Zeit. Wiss. Mikr., xx. (1903) pp. 17-20(1 fig.). 



f Tom. cit., pp. 12-4(1 fig.). 



% Page's Mag., iii. ( 1 003) pp. 99-104 (8 figs.). 



§ Amer. Journ. Sci., xv. (1903) pp. 227-32 (2 figs.). 



