356 Dr. W. Marcet on the Nutrition of 



men with a view to its ultimate elimination. The investigation 

 upon which I now beg to enter, extending over a period of about 

 five years, proved the correctness of this theory. A tissue is con- 

 stantly undergoing change. Very soon after it attains its highest 

 stage of development, or its state of maturity, it dies, and is 

 decomposed into crystalloids. Dr. Beale (^ Life Theories ' &c.) 

 believes that as soon as what he calls the bioplasm is transformed 

 into the insoluble matrix of a cell, it dies, then disappears, and 

 is replaced by other cells*. We may therefore regard tissues 

 as formed of three different materials : — (1) the nutritive ma- 

 terial which has left the blood and is on its way to become assi- 

 milated ; (2) the fully developed or ripe tissue ; (3) the material 

 resulting from the waste of tissues, which is on its way out as 

 effete matter. 



After much time and consideration had been devoted to the 

 available means of separating from each other these three diffe- 

 rent materials and effecting their analysis, I adopted the follow- 

 ing process, which answered the purpose most satisfactorily. 



If, say, 200 grammes of flesh be minced thoroughly and 

 mixed with 500 cub. centims. of water into a homogeneous 

 pulpy mass, there will be obtained, after straining through 

 calico or muslin, about 500 cub. centims. of extract (including 

 that wetting the calico), while about 154 cub. centims. of 

 solution will remain in the fibrous mass left in the calico. 

 This solution is estimated by drying the weighed fibrous mass, 

 the loss of weight so obtained representing the volume of the 

 extract without any material error. The total extract will there- 

 fore be equal to 654 cub. centims., and will contain : 



1st. The whole of the colloid material on its way to form 

 flesh; 



2nd. The whole of the crystalloid material resulting from the 

 waste of the tissue and on its way out of flesh ; 



3rd. Probably a small portion of colloid material in progress 

 of assimilation, which is squeezedoat by the process of extraction. 



The fibrous portion in the muslin, imagined dry and free from 

 extract, will represent a mass weighing rather less than 46 grms., 

 and consisting of colloid material assimilated and insoluble in 

 water plus a small portion of colloid material in process of assi- 



* Beale states : — " Every tissue may be divided anatomically into ele- 

 mentary parts [sic] . Each elementary part consists of the livirig matter or 

 bioplasm and the lifeless formed matter (cell-wall, envelope, tissue, inter- 

 cellular substance, periplastic matter) produced at the moment of the 

 death of the particles of the first." Beale, therefore, apparently considers 

 as dead organized particles what I have called ripe or mature tissue, which, 

 however, is on the point of becoming dead and lifeless. It appears 

 to me mature because it is in this state only that it can perform its 

 functions. 



