76 THE CONNECTIVE TISSUES, BY A. ROLLETT. 



by means of acids till neutralization is effected, it may again 

 be made to resume its original appearance ; a fact which 

 Henle first adduced against Reichert's view, who especially 

 rested his doctrine upon the absence of apparent structure in 

 the fibrillar connective tissue when acted on by acetic acid, and 

 on the impossibility of splitting connective tissue into fibres 

 otherwise than by mechanical means. The proposition of 

 Keiehert is also negatived by the facts already adduced. 



In reference to the capability of bringing back the fibrils and 

 bundles to their original condition after having been swollen by 

 immersion in acids, it must be remarked that the experiment 

 must not be too long delayed, since protracted action of acids 

 even at a low temperature, actually effects the solution of the 

 fibrils with formation of gelatine. It is further to be remarked 

 that, in solutions of pure alkalies, connective tissue in the first 

 instance swells up into the form of a transparent jelly, and that 

 at a later period the fibrils undergo complete solution. Con- 

 centrated nitric acid, at the commencement of its action, causes 

 the same sudden contraction of the fibres of connective tissue that 

 occurs at temperatures exceeding 140 Fahr. When covered 

 with chloride of calcium or potash, the fasciculi and fibrils 

 become hardened by the withdrawal of water. In solutions of 

 tannin a sufficient quantity of connective tissue soon removes 

 all the acid. Leather thus obtained, especially if the connective 

 tissue have previously been exposed to the action of lime, is 

 better adapted than when hardened by other means, for the 

 preparation of fine sections, to exhibit the arrangement of the 

 fasciculi in compact masses.* 



If in such sections the fasciculi, hitherto only considered in 

 the direction of their length, be cut across, the fine transverse 

 sections of the fibrils lying in close contiguity with one another 

 appear in the form of round or somewhat angular dots. This 

 view is, however, far better obtained if the fresh tissue be 

 allowed to freeze on a leaden plate, resting on an iron support, 

 and so imbedded in a freezing mixture that only the upper 

 surface is exposed, the sections being then made on the plate 



* Rollett, Sitzunysberichte der Wiener Akademie, Band xxx., p. 45, fig 

 3, Taf. 1. 



