Dept.'] NATURAL SCIENCES OF PHILADELPHIA. 11 



kind of pain; (e), Mental state; (/), Hectic fever; (g), Formation of hu_ 

 mors; (A), Modes of termination ; (i), Convertibility ; (/), Coexistence. 



The relations of cancer and tubercle to other growths may be readily summed 

 up. 



(III). Under the head of morbid anatomy may be mentioned (a), The the- 

 ory of special anatomical elements, characteristic of cancer and tubercle. 



(6), The theory that those elements are analogous to, or identical with certain 

 normal elements of the body. 



This latter theory is, perhaps, the most convenient, but there are some very 

 strong arguments against it, mainly derived from the preceding considerations. 



The object of this discussion has been to show that at the present time the 

 material at command is not sufficient for the establishment of any general law, 

 but that we must endeavor to accumulate evidence both from clinical obser- 

 vation and from minute anatomy, until some definite conclusion presents itself. 



II. Physiology. 



Drs. Hammond and Mitchell read a paper entitled ''Experimental Researches 

 relating to Corroval and Vao, two new varieties of Woorara, the South American 

 arrow poison.*'''' 



After detailing the history, mode of preparation, physiology and chemistry 

 of the woorara, the authors state their own experiments with the two new va- 

 rieties of this poison, obtained by Drs. Ruscheuberger and Caldwell of the 

 United States Navy, from the Rio Darien, Soutli America, and given to them 

 by Prof. Carson of the University of Pennsylvania. 



From these substances they obtained an alkaloid possessing when adminis- 

 tered in exceedingly small doses, all the power of the corroval or vao. The 

 corroval yielded a much larger per centage of this principle than the vao, which 

 accounts for the greater activity of the former. This alkaloid is uncrystalliza- 

 ble, but forms salts with many of the acids. AVhen pure it is of a very light 

 green hue, somewhat resembling tannin in appearance. It is intensely bitter. 



For this alkaloid they propose the name of corrovalia. 

 _ Numerous experiments were made with the corroval and vao, from which 

 the authors deduce the following conclusions : 



Corroval. 1st. That it differs essentially from any variety of woorara hitherto 

 described, both in its chemical constitution and physiological effects. 



2d. That it acts primarily upon the heart, through the medium of the blood, 

 producing an arrest of the action of this organ. 



3d. That it produces a cessation of the movements of the lymph hearts in 

 from twenty to thirty minutes after its introduction into the circulation. 



4th. That the annihilation of voluntary and reflex movements is a secondary 

 result of its action, depending primarily upon the discontinuance of the func- 

 tions of the heart. 



5th. That it acts upon the nerves from the periphery to the centre, .and 

 abolishes both the sensory and motor functions. 



6th. That it destroys muscular irritability. 



7th. That it paralyzes the sympathetic nerve, this being one of the primary 

 effects. 



8th. That it is absorbed both from the intestinal canal and skin of frogs . 



9th. That its poisonous qualities are due to an alkaloid hitherto undescribed. 

 Vao. 1. Vao, either in a solid, or more quickly in a liquid form, can be ab- 

 sorbed from the areolar tissues of cold-blooded animals, as the frog. 



2. It is also absorbed, if in solution, by the stomach, oesophageal mucous 

 membrane, rectum, and skin, .with a degree of rapidity which varies, and is 

 rapid or slow as the animal is well supplied with water. 



3. Warm-blooded animals absorb vao from the stomach and intestine when 



*See American Journal of Medical Science, for Ju!y, 1859, for this paper in full, 



1859,] 



