38 



is apt to be too irritating to a sensitive surface, but a weaker grade of 

 from 50 to 75 per cent should be preferred. To this the powdered sugar 

 of lead is to be added until no more will easily dissolve. The milky 

 fluid should then be well rubbed into the affected skin, and the opera- 

 tion repeated several times during the course of a few days. The itch- 

 ing is at once relieved and the further spread of the eruption is checked. 

 The remedy has been tried in a large number of cases and has always 

 proved successful. It must be remembered, however, that the lead 

 solution is itself very poisonous if taken internally. 



Much has been said in regard to the relative poisonous character of 

 these three plants. It has been generally claimed that the poison 

 sumac is the most poisonous, and that after it comes, first, the poison 

 ivy and then the poison oak. These conclusions were arrived at from 

 the occasional experience of individuals who were poisoned by handling 

 one species when supposedly immune to others. Experience teaches, 

 however, that immunity is somewhat variable in the same individual, 

 and therefore these general statements can not be accepted without 

 more careful experimental evidence. 



Restrictive and preventive measures. — It is highly desirable that legal 

 measures be adopted compelling the destruction of these plants 

 where they abound in places f popular resort. This can be man- 

 aged without much danger from the poison, and is a matter of very 

 general public interest. As has just been noted, many individuals 

 are practically immune from the effects of toxicodendrol. Advantage 

 should be taken of this fact to employ such individuals to remove these 

 plants from the vicinity of dwellings and from playgrounds. Much 

 of the work would be purely mechanical, consisting in rooting the 

 plants up by main force. This is the most certain method; the use 

 of concentrated sulphuric acid is attended with less danger, as the 

 plants do not need to be touched. A half teaspoonful should be applied 

 to the stem every two or three weeks in the springtime when the plant 

 is growing most vigorously. Care should be taken to keep the acid 

 away from the skin, as it is most highly corrosive. The brush should 

 in no case be left upon the ground nor used for fuel, and in burning it 

 in the field pains should be taken not to inhale the smoke nor to handle 

 the wood any more than necessary. 



The greatest care should be exercised in preventing workmen from 

 transferring the oil from their clothes and hands to other individuals. 

 To accomplish this object special suits should be worn, and the hands 

 should be washed several times a day with the alcoholic sugar of lead 

 solution described above. Bathing in hot water with strong soapsuds 

 is also strongly recommended. The clothing must also be well washed, 

 and it is always well to remember that towels may be a means of 

 conveying the oil. 



