439 



January, the end of March, the luiildle of April, the middle of June, 

 and the middle of August. 



The autlior proceeded to inquire carefully into the effects of season 

 iipon this species as it gi-ows wild in the neighboiirhood of Edinburgh, 

 but was surprised to find that every part of the plant in this locality 

 is destitute of narcotic properties at all seasons. The juice of a whole 

 pound of the tubei's, the part which has proved so deadly elsewhere, 

 had no effect when secured in the stomach of a small dog, either in 

 the end of October when the tubei-s are plump and perfect, but the 

 plant not above ground, or in the month of June when it was 

 coming into flower ; and an alcoholic extract of the leaves, and that 

 prepared from the ripe fruit, had no effect whatever when introduced 

 into the cellular tissue of a rabbit, under the same conditions in 

 which the Common Hemlock acts so energetically. By a comparative 

 experiment he ascertained that tubers, collected near Liverpool, where 

 one of the accidents alluded to above happened in 1782, act with 

 considerable violence on the dog ; and he briefly noticed some experi- 

 ments, made at his request by Dr Pereira, with the CEnauthe of 

 Woolwich, shewing that there also it is a powerful poison to the 

 lower animals. Climate seemed to the author to furnish the only 

 adequate explanation of these extraordinary diflerences ; yet the 

 plant grows in all parts of Scotland ■with great luxuriance. 



3. Cicuta virosa, Water-hemlock. — This species has been also held 

 to be a deadly poison ever since an express treatise on its eflects was 

 published by Wepfer in 1716; and repeated instances of its fatal 

 action have been observed since, and some of these very recently, in 

 Germany. The root is the oidy part which has given occasion to 

 accidents ; it has proved fatal in two hours and a half. Neverthe- 

 less, this plant too seems innocuous in Scothind, or nearly so, 

 although, like the last species, it grows with great luxuriance. The 

 juice of a pound of tlie roots collected in the end of July, while the 

 plant was in full flower, produced no narcotic svmptoms ; and the 

 only effects observed, namely, efforts to vomit, might have arisen from 

 the operation which is necessary to secure the juice in the stomach. 

 An alcoholic extract of the leaves collected at the same time, and a 

 similar preparation made with two ounces of the full-grown seeds, 

 while still green and juicy, had no effect whatever when introduced 

 into the celliUar tissue of a rabbit, except that inflammation was 

 exciteil where the extract was applied. 



4. The author has not yet had an opportunity of trying the effects 

 of the fourth species, ^thusa Cynnpiinn, or Foorsi)ai-sley. 



