PROCESS OF INVESTIGATION. 45 



to the fact, that the proportion of bioplasm in the 

 same tissue varies at different ages, and that in many 

 different forms of disease the morbid change essen- 

 tially depends upon a considerable increase in the 

 amount of bioplasm. These facts are most positively 

 demonstrated in specimens prepared according to the 

 method described. Moreover, I shall, by the aid of 

 this mode of investigation, be able to show where the 

 bioplasm ceases and the formed material commences, 

 and in some instances, to distinguish which part of a 

 mass of bioplasm was first and which last formed. The 

 action of the carmine fluid upon the bioplasm is well 

 illustrated by a well -prepared specimen of cartilage 

 of the frog or newt. The cartilage tissue, matrix, or 

 formed material is left perfectly colourless, and 

 although it consists of a firm, and not very per- 

 meable material, it has been freely traversed by 

 the carmine fluid. The rapidity with which a com- 

 paratively thick layer of the formed material may 

 be traversed by the dark red solution is very remark- 

 able. To illustrate this fact, a few cells may be 

 taken from the liver of a mouse recently killed. The 

 carmine fluid may be allowed just to pass over the 

 cells, and the excess at once washed away with a 

 little weak glycerine. The whole operation can be 

 performed in less than half a minute, and yet the 

 bioplasm of every cell, in this case called the nucleus, 

 will be coloured bright red, while the outer formed part 

 will be left colourless and unchanged. The formed 

 material in this instance consists of a thick layer of soft 

 matter, which, however, has been freely traversed in 

 the course of a few seconds by a fluid which contains 

 glycerine, and is of higher specific gravity than 

 blood- serum.* This enables us to form some idea of 



* The fluid which I use in the preparation of my specimens 

 has the following composition : Carmine, 10 grains ; strong 

 liquor ammonia, % drachm ; rectified spirit, | ounce ; Price's 

 glycerine, 2 ounces ; distilled water, 2 ounces. The carmine 



