SCIENCE 88, · VOL. 88, No. 2274 tM-3 n T18SUE+ C HINGE.FIG. I with the base and a membrane hinge...
Transcript of SCIENCE 88, · VOL. 88, No. 2274 tM-3 n T18SUE+ C HINGE.FIG. I with the base and a membrane hinge...
VOL. 88, No. 2274
tM-3
n T18SUE +
C HINGE
.FIG. I
with the base and a membrane hinge is cemnented on
(C). A writing lever (not shown in the illustration)is attached to the top surface. The bellows is nowmade ready for use by smearing generously a layerof paraffin oil on the membrane, thus not only sealingany microscopic holes, but rendering it more flexible.
These bellows may be made of any volume capacityto fulfil a particular conadition of recording. It shouldbe remembered that the more cubical the bellows ismade, the more amplitude will be recorded for a certainvolume change, and thus it is more sensitive but hasless mechanical advantage. A useful proportion isshown in the illustration.
J. R. DI PALMAJ. RAYMO:ND JOHNSON
DEPARTMENT OFB PHYSIOLOGY,LONG ISLAND COLLEGE OF MEDICINE
A SIMPLE FEEDING: DEVICE FOR CULEXPIPIENS IN AVIAN MALARIA STUDIESTHE meticulous and rather laborious procedures re-
quired for ~satisfa¢tory continuance of the mosquito-canary propagation of plasmodia in the laboratorysuggest that any simplification of methods should beplaced on record. The accompanying rough sketchesshow a device which has been very helpful in my ownwork through (1) eliminating the possibility of lossof mosquitoes by the toppling of a lantern globe off aPetri or crystallizing dish, and (2) providing a "bed"in which the bird lies very comfortably, indeed oftenquietly asleep, while the mosquitoes are feeding.There are, as shown, three simple parts to this device:first, a round flat base cut with shears from light-weight galvanized iron and having four projectingportions turned up at right angles, two of these lattersupporting upright hooks of stiff wire soldered againsttheir outer surface; second, a small piece of rubberizedcloth with a hole cUt in it eccentrically; and, third, arubber band. Without cloth, the band stretched be-tween the two hooks holds the globe and dish securelytogether; for blood feeding, the cloth is slipped be-
FIG. 1. A simple feeding device for Culex pipiens inavian malaria studies.
neath the strands of the band, the bird is laid betweenthe strands with its bared pectoral region over the hole,and the two sides of the cloth are brought together ontop and held in place by a pin.
HARRY BECKMANMARQUETTE UNIVERSITY SCHOOL OFMEDICINE
BOOKS RECEIVEDCATTELL, J. McKEEN and JAQUES CATTELL. AmericanMen of Science. A Biographical Directory. 28,000sketches. Pp. viii + 1,608. The Science Press. $12.00.
COREY, HERBERT. Submarine; The A utobiography ofSimon Lake. Pp. xiv+,303. Illustrated. Appleton-Century. $3.00.
DESHA, LUCIUS J. and LARKIN H. FARINHOLT. Experi-ments in Organic Chemistry. Pp. xi + 233. 23 figures.McGraw-Hill. $1.75.
EGLOFF, GUSTAV, MARTHA M. DOTY and JANE F. JORDAN.The Cracking Art in 1937. Pp. 397. Universal OilProducts Company, Research Laboratories, Chicago.
FULTON, J. F. Physiology of the Nervous System. Pp.xv + 675. 94 figures. Oxford University Press. $6.00.
HOGBEN, LANCELOT, Editor. Political Arithmetic; ASymposium of Population Studies. Pp. 531. Illus-trated. Macmillan. $9.00.
LEET, L. DON. Practical Seismology and Seismic Pros-pecting. Pp. x + 430. 185 figures. Appleton-Cen-tury. $6.00.
RASHEVSKY, NICOLAS. Mathematical Biophysics; Phys-icomathematical Foundations of Biology. Pp. xviii +340. 83 figures. University of Chicago Press. $4.00.
REID, ALBERT C. Elements of Psychology; An Introduc-tion. Pp. xix + 409. 94 figures. Prentice-Hall. $2.50.
SCHULTZ, HENRY. The Theory and Measurement of De-mand. Pp. xxxi + 817. 106 figures. University ofChicago Press. $7.50.
SHEPHERD, GRANT. The Silver Magnet; Thirty Years ina Mexican Silver Mine. Pp. 302. Illustrated. Dut-ton. $3.00.
STILLWELL, CHARLES W. Crystal Chemistry. Pp. x +431. 72 figures. McGraw-Hill. $4.50.
TATE, ALFRED 0. Edison's Open Door; The Life Storyof Thomas A. Edison: A Great Individualist. Pp. 320.Dutton. $3.00.
SCIENCE114
SCIENCE-ADVERTISEMENTS
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&MAiCtle?@
JU'LY 29, 1938 11
12 SCIENCE-ADVERTISEMENTS VOL. 88, No. 2274
An Entirely New Illumination Devicefor MICROSCOPES
PANCRATIC CONDENSERThe Zeiss Pancratic Condenser is a completeillumination system embodying the Kobler prin-ciple of illumination. Source of light and con-denser are contained in a single tube attachableto any make of microscope forming an ideal,,compact unit for the correct illumination formicroscopic work in transmitted light at differ-ent magnifications. With the Pancratic Condenser it is possible for the first time to synchro--nize instantaneously the numerical aperture of Cthe condenser with the numerical aperture of t0.5the respective objective within a range fromN.A. 0.16 to N.A. 1.40. In practice this pro-vides a smooth transition from illumination asneeded for low power work to the correct illu-'mination for medium and high powers. The
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