242 Notes and Memoranda. 



sages in Greek, Latin, or Hebrew, and speaking in some of the many dialects in 

 which he had learnt to converse in his youth. In the midst, however, of this vivid 

 resuscitation of the past, co-existing with the temporary oblivion of all recent 

 associations, it is a touchingly suggestive circumstance that he never forgot the 

 face of a friend." 



Diefeaction Expebiments. — Mr. Bridge informs us, with reference to his 

 apparatus described in our last number, that if the object-glass is removed, and 

 the point of light viewed with the telescope out of focus, a new series of appear- 

 ances may be obtained, and that by moving the object-glass to and fro to dif- 

 ferent distances from the eye-glass, a new form of figure is given by each posi- 

 tion. Many of the spectra Mr. Bridge considers would offer valuable sugges- 

 tions to designers of glass windows, carpets, etc. 



Microscope Lamp. — Mr. John Bockett sends us a photograph of his method 

 of mounting and using a microscope lamp. A pillar upon a foot carries a glass 

 lamp with a reflector behind it, and a condensing lens in front. The reflector is 

 about 3|-inches in diameter, and the bull's-eye condenser about 2 inches diameter, 

 and,' placed a little within the focus of the reflector. A shade is also provided. We 

 have long used and recommended the addition of a silvered reflector behind a 

 lamp. It not only economizes light, but for many purposes improves its quality, 

 as objects may be illuminated almost entirely by the reflected light when the wick 

 is turned low, and thus the glare of the direct flame is avoided. Mr. Bockett 

 burns Belmontine, which gives a whiter light than paraffine. 



PeopeetieS op MtrscrriAE Tissue. — Dr. William Marcet has communicated 

 to the Physical and Natural History Society of Geneva, a paper on the physical 

 properties of muscular tissue. He finds that it is a porous body, and feebly par- 

 ticipates in the properties of colloid substances. Its porosity allows it to be 

 traversed by solutions of albumen, which, however, only proceed through it at 

 half the rate of solution of phosphoric acid, thus showing that, like colloid bodies, 

 it opposes a certain obstacle to the transfusion of other colloids, and facilitates 

 the passage of crystalloids. Those to whom these terms are new should read the 

 paper on "Dialysis," Vol, i., p. 381. Physiologists will perceive the relation 

 which Dr. Marcet's researches bear to the question of the nutrition of muscles. 

 Dr. Marcet's paper appears in the Archives des Sciences, No. 86. 



Simplified Opthalmoscope. — Messrs. Smith, Beck, and Beck have intro- 

 duced a simplification of Liebreich's Opthalmoscope,, which renders this instru- 

 ment suitable for general use. The optical part is arranged in a single tube, which 

 carries both the mirror and the magnifying lens. The apparatus can be adjusted 

 to any height, and is fitted with a moveable arm, at the extremity of which is a 

 small lamp, furnished with a screen to keep the light off the face of the individual 

 under examination. A rest for the chin is also provided, and the whole packs 

 into a small case. 



Fossil Eqtjisetum in Gneiss. — M. Elie de Beaumont lately presented to the 

 French Academy a paper by M. A. Sismonda, on a block of gneiss, in the Turin 

 Museum, bearing the impress of a plant, which M. Adolphe Brongniart states is 

 allied to the Hquisetum infundibuliforme of the coal measures. He proposes to 

 name it Equisetum Bismondce. The block of gneiss appears to have been an 

 erratic from the Valtelline, and belonging to the infra Liassic group, which form 

 the general substratum of Alpine sedimentary rocks. At first M. Sismonda thought 

 the markings of a dendritic mineral character, but experiment and observation 

 showed them to be carbonaceous. The discovery of this fossil shows the rneta- 

 morphic character of the Alpine gneiss. 



