and Laboratory Methods. 1343 



Sections of the organs were tested for iron with ammonium sulphide and 

 with potassium ferrocyanide, with affirmative results. In the closer study of the 

 case Perl's test only was used. The routine method at first employed was as 

 follows : Potassium ferrocyanide, 2 per cent, solution, three minutes ; hydro- 

 chloric acid 1 per cent, watery solution, two to five minutes ; wash with distilled 

 water. The bulk of the material was hardened in Miiller's fluid to which 2 per 

 cent, formalin had been added, and was preserved in methylated spirits. With 

 the fresh tissue the reaction was prompt, but after two months no typical reac- 

 tion occurred, the granules turning green or a greenish yellow ; many did not 

 react at all. That the iron was not liberated, but that the reaction was only 

 delayed, was proved by the fact that sections left in the hydrochloric acid 

 solution, two to twenty-four hours, gave a typical Prussian blue color, while 

 when the test was performed with hot hydrochloric acid the reaction was almost 

 instantaneous. Sections kept in 4 per cent, formalin gave a typical reaction in 

 two minutes with cold hydrochloric acid. Bits of tissue hardened in alcohol 

 reacted readily. Miiller's fluid seems thus to have been the cause of the 

 delayed iron reaction. 



Four other cases of haemosiderosis were studied by the author. She con- 

 cludes that in general haemachromatosis some primitive agency, as yet unknown, 

 is at work leading to (a) an increased destruction of haemoglobin taking place 

 either in localized haemorrhages, or within the blood stream, or perhaps some- 

 times within the parenchymatous cells themselves ; (b) a degeneration of the 

 cells of certain organs by which they become unable to throw ofif the granular 

 pigment deposited in them, and, becoming loaded, finally disintegrate. The 

 cirrhosis would seem to be the nature of a chronic interstitial inflammation, 

 secondary upon the presence in the tissues of pigment set free after the destruc- 

 tion of the parenchymatous cell. j. h. p. 



GENERAL PHYSIOLOGY. 



Raymond Pearl. 



Books and papers for review should be sent to Raymond Pearl, Zoological 

 Laboratory, University of Michigan, Ann Arbor, Mich. 



Muhlmann, M. Uber die Ursache des Alters. This discussiop of the general physiology 

 Grundzuge der Physiologie des Wachsthums ^f growth begins with a comparison of 

 mit besonderer Beriicksichtigung des Men- o o 



schen. Wiesbaden (J. F. Bergmann), pp. thebiological relations of unicellular and 

 xii und 195, mit 15 Abbildungen, 1900. multicellular organisms. From the two 



premises that, on the one hand, the differences between unicellular and multicel- 

 lular organisms are the results of the close proximity of the cells to one another 

 in the latter as compared with the former, and, on the other hand, that one most 

 important difference between the two is that the multicellular organism dies, 

 the author arrives at the conclusion that growth causes death. This preliminary 

 statement of the general standpoint opens the way for an analysis of the laws of 

 growth. The subject is developed in the following way : Growth is primarily 



