170 THE AMERICAN MONTHLY [August, 



nective, or other tissue, illustrated in the web which we examined, is 

 alike composed of cells or units of protoplasm ; vital tissue being there- 

 fore a mass of protoplasm. 



Protoplasm exists only under certain conditions of environment ; it 

 is continually undergoing change (metabolism) ; its very existence de- 

 pends upon its property of utilizing certain nutrient substances provided 

 by various means for sustenance, and at the same time the effete products 

 of its vitality must be removed. 



We thus have assimilation and disassimilation as necessities, which 

 are associated with every protoplasmic particle, from the unicellular 

 amoeboid forms to the multicellular and more complex organisms of the 

 mammalian type. This condition prevails, viz : that protoplasm, 

 whether in the simpler or more complex organisms, receives its pabu- 

 lum from its immediate environment. The living cell, vegetable or 

 animal, is surrounded with a medium which provides material for assim- 

 ilation. In the lower forms of life the micro-organism, bacterium, mi- 

 crococcus, or spore, in aqueous surroundings, secures the oxygen neces- 

 sary to its existence from the fluid in which it moves. In the higher 

 organisms the circulatory fluid provides a similar condition, supplying 

 to each cell its pabulum, enabling it to fulfil its function as well as re- 

 tain its vital principle or condition. The microscope enables us to 

 study the morphology of the cell and tissue, to note the varying aspects 

 from the nucleolus to nucleus, to the variously formed tissues of the 

 complete organism. Illustrations of this truth might be represented by 

 the admirable study of the nucleolus and modifications in the living cell 

 by Dr. W. H. Dallinger (Proceedings Royal Microscopical Society), 

 wherein the varying vacuolar manifestations and movements of pro 

 toplasmic granules demonstrated that the extra vital substance was 

 associated with the nucleolus. Another instance would be the work re- 

 corded by the embryologist, wherein the manifestations of vital changes 

 from the embryo to various tissues, and growth to organs and the fully 

 developed organism, is known to the minutest detail, and yet we must 

 deplore that the vital principle, the immediate and present cause of all 

 these changes, is beyond the power of the microscope to reveal. 



The microscope might possibly indicate a slightly hyaline appearance 

 to the living cell not present after life has departed, produced by the 

 coagulated state of the protoplasmic mass. Herein lies one of the diffi- 

 culties met with in the investigation of the subject ; many reports indi- 

 cate that in the death of animals (death of protoplasm) by powerful 

 electric influence no modification of the tissue is discernible with the 

 microscope. This is yet sub judice. Chemistry may help us here. 



The composition of the tissue of the body has a marked bearing on 

 the subject we are reviewing. As we are considering the relation of 

 electricity to animal protoplasm, we will take up the more important 

 substances relating to the composition of the tissues making the great 

 bulk of the animal organism. That of greatest fluidity, the blood, has of 

 water about 75 per cent., a fair percentage of salts chiefly components 

 of potash and phosphoric acid (C. Schmidt). Muscular tissue, which 

 forms a very large proportion of the bulk of the organism, has a jelly- 

 like consistence. 



The capillaries in the muscle form a fine net-work which in the 

 active state of the muscle similates somewhat that condition of conges- 



