168 Scientific Intelligence. 
ponds at a scale distance of 2700™™ to of anampére. With 
1 a 
compensating magnet 0°1™™ deflection to of an ampére. 4 
12 
10?° 
seag ghag of 10° C. between the junctions of one german silver 
and iren thermo-element gives a deflection of 120™™ throng 1000 
eis. resistance at a scale distance of rue ».—Annalen fees 
Physik und Chemie, No. 12, 1884, pp. 677-6 
12, Electrical resistance of microphone ¢ contacts PRE mo in 
ment.—The theory of the action of the rophone is still little 
manures. Otto Boekman, in his p: Abee gives the results of 
aurea strengths, a ith varying pressure upon the contacts. 
The results are expr an graphically, and the author concludes 
that the resistance of polished carbon contacts, under constant 
pressure and with constant current strengths, is smaller during 
movement than during rest. Afi ssation of the movement 
ished strength of tone of the tuning fork interr upter, the mor 
the strength of the electrical current remaining the same. 
The resistance during the movement is with same stren " of 
tone and strength of current not dependent upon the num 
vibrations, whic the movement indicates—it is also inde pended! 
of the pitch.— Ann. Phys. Chem., No. 12,1884, pp. 651-665. J.T. 
13. Resistance of the Siemens Mercury unit—H, Wild comm 
nicates in detail the results of his new measurements of the mer 
cury unit and obtains the value 1. S. E.=0°94315 ohm, and there 
fore concludes that 106-027" of mercury, one square millimete? 
in section at 0° C., represents the resistance of an ohm,--Annalen 
der Physik und Chemie, No. 12, 1884, pp. 665-677. J.T. 
II. GroLtocgy anp Naturaut History. 
. A Scorpion from the Upper Silurian. — A fossil Scorpio? 
ee been found in the Upper Silurian (Ludlow) of Gotland, 
Sweden, and named MM. i 
nuncius, The specimen is well preserved and shows clearly the 
cephalothorax, the abdomen with seven dorsal plates, and ee ‘ 
call, consisting 0 ai segments, the last pointed to form he 
poison-dart sculpture of the surface consists of tubere 
and longitudinal ridges, and is exactly as in recent scorpions 
One of the Per is visible on the right side, proving that the 
animal respire . 
Further, a + feaail scorpion was obtained last year by Dr. 
