396 THE AMERICAN MONTHLY [Dec. 



In presenting this apparatus to the academy, in behalf of Mr. 

 Fremont, Mr. Marey recalled the experiments that he had made 

 toward reproducing microscopicbeings by chromophotography. 

 With ordinary illumination the objects detach themselves from 

 a luminous ground and successive photographs of them can be 

 taken only upon a movable film. The series of images thus ob- 

 tained, include, it is true, all the data necessary for determining 

 the changes of form and position of the object in motion; but in 

 order to appreciate such changes, it requires considerable labor 

 in the way of comparing the images, which are intimately con- 

 nected in a long series. For such studies it would be prefera- 

 ble to have recourse to chromophotography upon a dark ground, 

 which, upon the same immovable plate, reunites the successive 

 images of the object. 



This method, which has been applicable only to objects of 

 large dimensions, will, perhaps, owing to Mr. Fremont's new 

 instrument, be applicable to microscopic photography. Should 

 such be the case a great progress will certainly be made in our 

 knowledge of the motions of microscopic beings. — Scientific 

 American. 



MICROSCOPICAL MANIPULATION. 



A New Borax-Carmine. — Everyone who has worked at 

 botanical microscopy has fretted at the difficulty of using borax 

 carmine in staining plant sections. It is a splendid stain, but 

 to get satisfactory work with it, it is necessary to practically 

 destroy all cell contents and consequently is useful only in 

 skeleton preparations. Professor Radais, of the Ecole de Phar- 

 macie, Paris, has recently discovered a mode of preparing the 

 reagent which entirely obviates this disagreeable trouble. His 

 process as communicated to the Journal de Pharmacie, is as fol- 

 lows : Put in a balloon, arranged with reflux refrigerating ap- 

 paratus, a mixture of pulverized carmine (No. 40) , 2gm. ; borax 

 8gm.; alcohol of 70°, 200 gm. and heat on a water-bath. Let 

 the alcohol boil for twenty minutes, then cool slowly and filter. 

 The alcoholic tincture should index exactly 70° alcoholometri- 

 cally, and where a good condensing apparatus is not at hand 

 use alcohol of 71° or 72°. The reagent keeps well in closely 



