PRELIMINAKY. 5 



this preparation, he introduced between the plates of glass 

 a drop of sulphuric acid (1 eq. of acid being mixed with 

 4 eqs. of water), and he was then able to follow the process 

 of disaggregation which marked the arrival and passage of 

 the acid ; an orange tint, brown next the tissue which con- 

 tained quaternary substance in abundance, was first visible ; 

 then in the rest of the tissue were seen the first dissolving 

 reactions finishing the effect of the tincture of iodine ; the 

 cellulose became gradually divided into groups of amylaceous 

 particles, which gave a beautiful violet-coloured outline to 

 the cylindrical cells radiating or spread out symmetrically 

 from the points of insertion of each joint/' 



