1904.] Properties of Solutions of Chloroform in Water, etc. 383 



for these substances are not present in demonstrable quantity in by- 

 far the greater number of animal and vegetable cells. 



Turning to the views of anaesthesia which rest upon an interaction 

 between the anaesthetic and the cell-protoplasm, we find the speculation 

 first thrown out by Claude Bernard* in 1875, that anaesthesia consists 

 in a semi-coagulation of the substance of the (nerve) cell, a coagulation 

 which may not be definite, that is to say, in which the substance can 

 return structurally to its primitive state after elimination of the toxic 

 agent. Bernard supports his view chiefly by analogy, and instances 

 the stiffening and opacity of skeletal muscle when exposed to 

 chloroform vapour. 



A similar view was expressed by Binz,f who stated that sections of 

 cerebral cortex placed in 1-per-cent. solution of hydrochlorate of 

 morphia soon showed a cloudy appearance, and fine granules appeared 

 in the nuclei; the protoplasm also became granular. The stage at 

 which the cell-protoplasm was merely cloudy, and not discretely 

 granular, could be recovered from by washing away the morphia, but, 

 when once the granules appeared, they could not be made to dis- 

 appear again. Similar results were obtained by exposing cortical 

 nerve-cells to vapour of chloroform, or to solution of chloral hydrate. 



Neither Binz nor Bernard showed, however, that there was any 

 precipitation or semi-coagulation at or near the concentrations which 

 correspond to anaesthesia, nor were the optical methods used capable 

 of demonstrating effects upon the protoplasm short of precipitation. 



Similar speculations of a general nature regarding the action of toxic 

 agents, as being due to the formation of a loose, easily-dissociated 

 compound between the toxic agent and the cell-protoplasm, have been 

 thrown out by various writers, as, for example, Buchheim (1856) and 

 Schmiedeberg (1883). 



Demoor J has shown that, subsequent to prolonged and deep 

 anaesthesia, the dendrites of nerve-cells acquire moniliform swellings, 

 and has founded on this a mechanical theory, which rests on the view 

 that the swellings observed are due to a retraction of the protoplasm 

 of the dendrites, so that the communication of cell with cell is inter- 

 rupted. 



The swellings described by Demoor have also been observed by 

 Hamilton Wright,§ who also found that they became larger, more 

 numerous, and encroach more and more on the dendritic stems the 

 longer the anaesthesia is kept up. 



These effects are of importance as evidence of an interaction between 

 protoplasm and anaesthetic, but the retraction theory of Demoor based 



* ' Lecons sur les Anesthesiques,' etc., 1875, p. 153. 

 f ' Vorlesungen uber Pkarmakologie,' p. 175. 

 X ' Arch, de Biol.,' 1896, vol. 14. 



§ ' Journ. of Physiology,' vol. 26, 1900, p. 30 ; vol. 26, 1901, p. 362. 



