PATHOLOGY. 133 



CHAPTER X. 

 PATHOLOGY. 



Pathology of Serpent Venoms. — The pathology of snake poisoning in man owes 

 most of what is hest in our knowledge of it to the researches of the East Indian 

 surgeons and to American observers. 



In the following observations Prof. H. F. Formad has followed with great suc- 

 cess the lines of a research which were laid down with care by the authors of this 

 essay. They have also been at great pains to repeat, and to verify, most of the 

 observations made by this distinguished observer. 



The Nature and Character of the Individual Morphological Constituents of 

 Venom. — Having seen that fresh venom consists morphologically of a liquid and 

 of a solid part, it was necessary to ascertain the exact nature and character of 

 each. 



The following means were resorted to : — 



1st. The separation of the granular material (of fresh venom) by filtration and 

 the submission to physiological tests of the liquid filtrate and of the solid residue, 

 each separately. 



2d. The exposure of fresh venom to a temperature high enough to kill organized 

 life, and then submitting it to physiological tests. 



3d. Studying the effects of venom and of its isolated morphological constituents 

 upon dead animal substances. (Putrefaction and other experiments.) 



4th. The isolation and culture of the organisms contained in venom and the 

 testing of the physiological effects of these isolated and washed organisms (viz., of 

 pure cultures of micrococci). 



1st. Filtration Experiments with Fresh Venom. — On account of its viscid and 

 glutinous character venom could not be satisfactorily filtered except under a high 

 pressure through a vacuum filter. About two drachms of fresh Crotalus adamanteus 

 venom were forced by means of a hydraulic air pump through a porous clay cylin- 

 der such as is employed in certain small galvanic batteries, or else the venom 

 was filtered through a thin layer of plaster of Paris moulded in the neck of a 

 small glass filter. The liquid filtrate obtained was perfectly clear, and examined 

 under the microscope showed no organic or solid particles of any kind. The solid 

 residue left upon the filter consisted of granular material, such as has been described 

 before, of bacteria and a few cells. This residue was diligently and repeatedly 

 washed with boiled distilled water, by passing the latter through the filter. 



The amount of residue (about three grains) just obtained was dried and intro- 

 duced subcutaneously into the pectoral muscle of a pigeon, but without effect. 



