662 SUMMARY OF CURRENT RESEARCHES RELATING TO 
be obtained of the occurrence of fluor-spar of similar quality at 
Oltscheren. The crystal seekers, M. Ott and C. Streieh, of Guttanen, 
as well as the hunter Caspar Blatter, were at once commissioned by 
Prof. Abbe to make investigations in the neighbourhood, but it was 
not until the spring of 1887 that they succeeded in rediscovering the 
old locality of 1830. A new locality was also discovered, from which 
beautiful green crystals, varying in size from 1 cm. in diameter to one 
over 20 cm. in length, were obtained. The surface of most of these 
specimens was rough, many being covered with irregular holes, while 
others looked like ice which had begun to melt in the sun. These 
specimens were offered for sale by Ott and Streieh without the know- 
ledge of Prof. Abbe, and were purchased by the authorities of the 
Bern Museum. Of the material sent to Prof. Abbe at Jena very little 
was found to be fit for optical use. The authorities of Brienzwyler 
now took action and prohibited further search for useful minerals in the 
district under their jurisdiction. An agreement was then drawn up by 
them with a company of capitalists, at whose head stood the firm of 
Zeiss, in Jena, and Prof. Abbe, by which the exclusive right of search 
for fluor-spar in that district was granted to the latter. The stipu- 
lation was, however, made that all material unfit for optical purposes 
should become the property of the authorities. The company began 
work in the summer of 1888 under the directorship of Herr Kable of 
Jena, who was stationed in a hut on the Alp Buhlen. According to a 
letter of Prof. Abbe to the author the old find of 1830 came from 
two cavities on the south part of the mountain. The lower one was 
easily accessible, but the other, high above, could only be reached by a 
72 ft. ladder from another projecting rock mass. Both were found to 
have been exhausted, and further search for fluor in the neighbourhood 
only met with indifferent success as regards quality. In conclusion the 
author describes the visit he himself paid to the locality under the 
guidance of Caspar Blatter and Herr Kable. Starting from Meyringen 
with Blatter he passed by Prasti, Schiittelboden, Laui-Vorsass, and 
Platten to Buhlen, where Herr Kable was installed. With the latter he 
then proceeded through the valley of Oltscheren to the upper Alp 
Oberfeld, whence could be seen the south slope of the Oltschikopf, with 
the two cavities, from which came the extraordinary find of 1830, plainly 
visible. 
Johnston, C. — The American Objective as compared with the German. 
Maryland Med. Journ., XXI. (1889) p. 130. 
C3) Illuminating- and other Apparatus. 
Object-carrier with Vertical Displacement for the Jung Micro- 
tome* — Prof. L. Koch points out that the object-carrier hitherto used 
only allows a comparatively slight elevation (J to 4 mm.) of the object 
adjusted. This is due to a great part of the slide-way being occupied 
by the micrometer screw and the object-carrier. In fact, for the object 
itself, the displacement is only about a millimetre, since often more 
than a millimetre of paraffin has first to be removed, and, if the course 
Bot. Centralbl., xl. (1889) pp. 283-5. 
