OF THE VENOM OF THE RATTLESNAKE. 51 



Later in the year, during the month of September, and early in October, I re- 

 peated these experiments upon the following plants, viz : — 



A young shoot of the common bean, four inches high. 



A young dahlia six inches high, and constituting the whole plant. 



A long flower, or budding flower-stalk of medicinal colchicum, C. Autuninale, 

 about ten inches high. 



Three branches of geranium, growing on a large and healthy plant. 



A small succulent garden weed, three inches high, of a species unknown to me. 



I had no duplicates of the dahlia, bean, and weed mentioned above, which I 

 could wound as a means of comparison, but in the case of the colchicum, I wounded, 

 without poisoning, the remaining flower-stalk, which was rather more fully in 

 bloom, and in the geraniums I wounded, in like manner, three branches, of sizes 

 about equal to those of the stalks which I both wounded and poisoned. 



The mode of introducing the venom, which, in these cases was perfectly fresh, 

 and of tried and known potency, I varied in several ways. In the dahlia and col- 

 chicum I merely raised the outer bark longitudinally, and with a fine pipette slip- 

 ped one drop of venom into the opening. I then bent the stalk slightly, so that 

 the divided bark would rise a little from the surface beneath, and thus hold the 

 venom by capillary attraction. 



The weed was inoculated by splitting it near to the earth, and inserting a full 

 drop of venom. The geranium branches were each surrounded by a little \\\) of 

 wax, withiH which I put from one to two drops of the venom, and then filled the 

 cups with four or five drops of water, having previously punctured the stems, so 

 as to place the incisions below the level of the poisoned water. The water was 

 renewed twice a day, and into one of the geranium branches I introduced, three 

 days later, about one-third of a drop of venom, just above the wax. The cups fell 

 off after four or five days, but neither in the bean, dahlia, colchicum, or geranium, 

 did the leaves die, or the plants in any way suffer, although they were watched 

 daily, during three weeks. 



The weed alluded to was an accidental growth in the pot with the geranium. 

 It appeared to di'oop two days after the poisoning. This was due, I presume, to 

 a very cold night, after which the plants were carried into the house, when the 

 one in question very soon revived. In many successive efforts to poison other 

 plants with venom, I failed in every instance. 



It is clear from the foregoing statements, that the venom of the Crotalus is not 

 fatal to the growth of the loioer orders of vegetable existence; but, unfortu- 

 nately, no such definite inference can be drawn with regard to plants higher in the 

 scale. My own experience, it is true, would, if considered alone, entitle me to 

 assume the inactivity of Crotalus venom within the tissues of the plants essayed, 

 and this conclusion would gain value, also, from what we know of the mode of its 

 influence upon animals, and from the facts which we have made known as to the 

 power of some forms of vegetative life to defy its influence. But, in the face of 

 strong aflirmative results, such as were obtained by Dr. Salisbury, I am unwilling 

 to draw from my own negative experiments the same definite opinion which I 

 should otherwise have felt authorized to base upon them. As I was indisposed to 



