OBITUARIES 69
The author prefers the electrocautery to the Paquelin thermocautery whenever cauterization is resorted to.
W. H. Crisp.
A quantitative study of achromatic and chromatic sensitivity from center to periphery of the visual field. Presented to the faculty of Bryn Mawr College in partial fulfillment of the requirements for the degree of doctor of philosophy. By Hazel Austin Wentworth. 192 pages, illustrated. Paper covers. Published for the American Psychological Association by Psychological Review Company, Princeton, New Jersey.
The work included in this dissertation is to some extent along the lines of studies published by Ferree and Rand in the Archives of Ophthalmology and the American Journal of Ophthalmology.
The chromatic thresholds were determined under light and dark adaptation. The achromatic thresholds were determined with a completely dark-adapted eye at the same points in the field as were used for the chromatic thresholds. Special attention was given to variations in the light and color sensitivity in the dark-adapted eye in and around the macula.
The following results of special importance may be mentioned here: The sensitivity to yellow in the different quadrants was found to be from 276 to 5,170 times as great at the center as at the periphery. From point to point in a given meridional quadrant and at corresponding points in different meridional quadrants there were great irregularities in the ratios of sensitivity to different colors; small regions of decreased sensitivity to one color being found with no loss of sensitivity to the other colors. With a high intensity of stimulus the limits of chromatic sensitivity to yellow were found to be coextensive with those for white light vision ; and at all intensities, with stimuli equalized in energy, the limits for yellow fell outside those for red, blue, and
green. The interlacing of limits for red, blue, and green is not necessarily a pathological phenomenon but rather a characteristic relationship for the normal eye. A general tendency was found for the area of the color fields to vary with the logarithm of the intensity of the stimulus light. Under dark adaptation, color sensitivity was found not to extend to the periphery for all wave lengths. The retina was most sensitive to green at every point investigated, and the ranking as to sensitivity from highest to lowest was in general green, yellow, blue, red, except that at the fovea and at a point in the nasal quadrant five degrees from the fovea the sensitivity to blue was greater than to yellow. W. H. Crisp.
Handbuch der gesamten Augenheil-kunde; sections 491 and 492, continuing Die Krankheiten der Orbita (Diseases of the orbit). By A. Birch-Hirschfeld. 154 pages, illustrated, 16.80 marks. Verlag von Julius Springer, Berlin, 1930.
This continuing section is a fragment of the chapter on diseases of the orbit, which it carries from page 895 to page 1048; the total number of pages in the whole chapter being 1048. It contains the indexes for this chapter and for the chapter on pulsating exophthalmos.
W. H. Crisp.
OBITUARIES David Nichols Dennis
On November seventeenth last ophthalmology lost one of its most highly esteemed and distinguished representatives in the death of Dr. David Nichols Dennis of Erie, Pennsylvania. He had been in ill health some years before and had been obliged to take an extended rest, but he had recovered and resumed active practice when the end came.
Dr. Dennis was of a class of scholarly physicians, now unfortunately growing fewer, whom the medical profession can ill afford to lose. A man of fine medical attainments, thoroughly