18S2.J 



MICROSCOPICAL JOURNAL. 



195 



August, and became manifest the 

 next day after a ramble in the woods, 

 but not so far as is known in contact 

 in any way with this poisonous plant. 



The microscopical characteristics 

 Avere throughout such as have been 

 described, and I especially noticed 

 the constant occurrence of the organ- 

 isms in the white blood-corpuscles, 

 and as this was at the time a new 

 thing to me for any disease, much 

 attention was paid to it. 



With these two series of facts be- 

 fore me — the occurrence of bacteria 

 in the tissues of living plants and 

 their presence in the exudations of 

 inflamed surfaces of the human body 

 in consequence of having touched or 

 been in the vicinity of certain plants 

 — it was most natural to connect the 

 two together on the subject. Accord- 

 ingly, during the month of Septem- 

 ber, 1881, I gathered some of the 

 freshest, cleanest leaves that could be 

 found at that season of the year of 

 Rhus toxicodendron, and carefully 

 washed them in a little pure water. 

 This water being then examined was 

 found to contain several kinds of spores 

 of fungi, and many minute, shining 

 spherules, indistinguishable from the 

 Micrococci found in the blood-serum 

 before mentioned. This was fol- 

 lowed by an examination of the 

 fresh juice, taken so as to prevent 

 contact with the exterior of the 

 plant, and here, too, minute moving 

 bodies were found in great numbers, 

 though the majority of the latter are 

 really little resinous globules. To 

 complete the proof, it seemed to me 

 desirable to directly apply these organ- 

 isms from the plant in as pure a state 

 as possible to the skin, and observe 

 their effects. I had supposed myself 

 exempt from the bad effects of the 

 poison and had little fear of the 

 experiment. I therefore carefully 

 cleaned off the outer bark of a fresh 

 stem to remove anything adhering to 

 the exterior, cut the stem across and 

 quickly secured a small amount of 

 the exuding milk-sap, which was 

 at once transferred to about a hun- 



dred times its bulk of distilled 

 water. When well mixed, the fluid 

 had only a slight milkiness of appear- 

 ance and could not have contained, 

 thus diluted, enough of any purely 

 chemical poison known, to have seri- 

 ously injured the skin or flesh. Still, 

 under the microscope, there appeared 

 many of the moving atoms. I then 

 applied a small amount of the infu- 

 sion to my arm, having first desig- 

 nated the spot by clipping the little 

 hairs growing upon it. The area 

 covered was not over one-third of 

 an inch in diameter, and the water 

 dried away in about one minute. 

 On awakening the next morning, 

 eighteen hours after the application, 

 the spot was evident from its redness, 

 and there was a slight sensation of 

 heat in the part, both of which symp- 

 toms rapidly increased, becoming 

 very evident by the twenty-fourth 

 hour and accompanied with itching. 

 By the forty-eighth hour my arm was 

 much inflamed and somewhat swollen 

 over an area about four inches 

 across. Miliary vesicles arose, but 

 there was very little serum exuded. 

 The inflamed surface increased in 

 size during some six days. To more 

 fully test the infectious nature of the 

 disease I placed a little of the exuda- 

 tion on a remote part of my body, 

 and had the satisfaction of having 

 another place to appease by friction. 

 After about ten days the malady had 

 evidently run its course and gradu- 

 ally abated. 



Now I was satisfied that this was 

 very much worse than it would have 

 been upon my hands, except perhaps 

 where the skin was especially thin, 

 as between the fingers ; on the 

 palmar surfaces no effect whatever 

 was or, I believe, ever is produced. 

 I was also abundantly satisfied with 

 one experiment, not caring to repeat 

 the process for the sake of comparing 

 results. 



Once in midwinter and once in 

 August, 1882, I examined the juice 

 of this poisonous Rhus without find- 

 ing the micrococci, yet after handling 



