1835. Improvements in Science. 213 



fibres, which partly run in a winding manner, parallel 

 to each other, and partly cross each other obliquely in 

 such a way that they can be traced through their cross- 

 ings. The first appear especially in the longitudinal clus- 

 ters in the base of the brain, the latter in the limits of the 

 white and gray substance of the brain. These fibrils have 

 generally a diameter of J^o t0 64o °f a l me > Dut at intervals 

 they swell into knots which are 2 Jo in thickness, and consist 

 of an extensive, tough, transparent substance, soluble in 

 water, and of spherical, slightly transparent, white, ner- 

 vous globules, which possess a diameter of from 6 } to ^ 

 being roundish or oblong. In the thin fibrils the globules 

 lie in one row, but in the thicker fibres two or more are 

 arranged abreast without forming regular rows. In many 

 parts of the nervous substance, as in the slices of the cere- 

 bral mass, few or no parallel fibres are detected, while 

 globules either of a cylindrical or elliptical form may be 

 observed. In the grey matter the globules are heaped to- 

 gether, and occasionally may be noticed transverse fibres, 

 or their curved oblique courses traced. The knots of the 

 fibrils Ehrenberg considered to be bladders. Krause, how- 

 ever, concludes that the fibrilli are solid cylinders and not 

 tubes, because in the globules magnified 1000 times, he saw 

 an outer border of the circuit, and on the cut edges of the 

 brain and nerves which contain longitudinal and transverse 

 fibrils, and therefore must be cut through. He never could 

 observe light by magnifying to the highest degree, and by 

 every possible change of illumination. 



He considers water an improper medium through which 

 to view the globules, because, as in the blood, their form is 

 altered by that fluid, and he recommends the fresh serum 

 of the blood and water holding in solution albumen. 



Professor Ehrenberg, in answer to Krause, states that he 

 has made observations with and without water upon the 

 nervous substances, and by the aid of an instrument much 

 more powerful than that employed by Krause, and has found 

 them steady, and still adheres to the opinion that the fibrilli 

 are tubes. 



Combination of albumen with metallic oxides, albumen, and 

 chloride of mercury, by F. Rose. — The precipitate by albu- 

 men in a solution of chloride of mercury is soluble in an 



