24.2 "dr. beale^ on the tissues, 



a membrane. It is true^ that some of the blood- corpuscles 

 are incorporated in the crystalline mass^ and may be seen 

 for some time amongst the red crystalline matter, but these 

 are entire corpuscles — probably young ones — not merely 

 cell-walls. These facts permit us to take a very simple 

 view of the development, nature, and offices of the red 

 blood- corp u scle . 



A2^pearance of a cell-wall produced artificially. — In the 

 kidney^ and indeed in many other structures, there is the 

 same difficulty in satisfying oneself as to the existence of a 

 ceU-wall. The well-defined outline exhibited when elementaiy 

 parts are placed in water, which is received by many as 

 evidence of the presence of a cell- wall, can be exactly imitated 

 artificially. The urea having been separated, filter off a little 

 of the remaining constituents of urine with the extractive 

 matters, and v/hen this solution is moderately concentrated, 

 add nitric acid, so as to be quite sure that no living structures 

 can exist, evaporate the mixture to the consistence of syrup, and 

 you will very frequently find a number of bodies which might 

 be readily mistaken for cells. It would be very instructive 

 to make a series of such artificial products in different Avays, 

 for many forms closely resembling the so-called animal cells 

 woidd be found. Such facts as these, and the changes which 

 he has observed to take place in particles precipitated from 

 fluids, have caused Mr. Rainey to come to the conclusion. 

 Dr. Beale thinks prematurely, that the growth of bone, and 

 even of some of the soft tissues, may be explained on physical 

 and chemical grounds alone."^ 



These observations of Mr. Rainey^s are most interesting 

 and most important ; but in all the tissues which the author 

 had examined he has had no difficulty in demonstrating the 

 existence of living matter, and without this li^dng matter the 

 tissue never could be formed. Indeed, he would assert, with- 

 out fear, that in every living tissue there is germinal matter 

 and formed material. The germinal matter may die, when 

 the formed material has reached a certain thickness ; but this 

 formed material was, in all cases, once in the state of ger- 

 minal matter, and coidd never have been produced except as 

 the result of changes taking place in living particles. 



Although in many structures it is difficult to prove the 

 existence of a cell-wall, in others there can be no question as 

 to its presence. In the mildew it is distinct enough ; but it 



* ' Oa the Mode of Formation of Sliells of Animals, of Bone, and of 

 several other Structures, by a Process of Molecular Coixlescence, demonstra- 

 ble in certain artificially formed Products,' by George Raiuey, M,E,.C.S. 

 1858. 



