On the Advantage of Perlscopic Spectacles. 165 



Two drachms of a decoction of the root of the Vcratrinn 

 injected into the veins of an animal, throw it immediately 

 into convulsions, and produce vomiting followed by death, 

 and almost at the same moment a state of flaccidity. 



A spirituous infusion, according to llaller, has more 

 strength than an aqueous, and the latter more than a de- 

 coction or an extract. There is reason to believe that the 

 activity of this plant resides in the volatile parts which the 

 boiling disengages. 



Under the article black licllebore, Hellehorus v'lridis of 

 Linnajus, Haller says also that this plant serves to poison 

 arrows ; and he quotes Monardus, who relates that a 

 chicken died in consequence of a fibre of black hellebore 

 being made to pass through its crest. So deleterious an 

 action, however, can hardly be allowed to this hellebore, 

 since in the time of Columella the root of it was emploved 

 to make setons for cattle, which were made to pass through 

 the skin, and particularly of the neck, and thereby excited 

 suppuration. 



In regard to wolf's-bane, the following observation, 

 on that species called by Linnaeus Acon'ituin cummarumf 

 occurs in the work of Haller : — The juice of this plant 

 having been accidentally introduced into a wound, in a very 

 small quantity, it produced cardialgia, syncope, swelling, 

 and at Icntrth tranorrene of the arm. 



O p o 



It appears from these facts, that the three plants above 

 mentioned, but chiefly the Veratrum, were those emploved 

 by the antient inhabitants of Europe for poisoning their 

 arrows ; and that the introduction of fire-arms made them 

 gradually abandon the use of this poison, which was still 

 employed by the Spaniards in the seventeenth century. 



XXVIII. Experiment shouin^ the Advantage of Perhcopic 

 Spectacles. Bij W. H. Wollaston, i\L D. F. R. S. 



To Mr. Tilloch. 



SIR, 



jl me opinion given by Mr. Jones, in your last Magazine, 

 respecting the improved form of spectacle-glasses, on 

 which I had delivered my sentiments in the preceding 

 number (p. 327), induces me to trouble you once more 

 opon that subject. 



It is wholly unnecessary to make any reply to the varl- 

 L 3 ous 



