32 MR. J. BLACKWALL ON THE POISON OF 



ment was in progress, stood at 76° ; the air throughout the day was sultry, and an exten- 

 sive thunder-storm occurred in the evening. 



A highly exasperated female Epeira diadema was allowed to seize me on the inner side 

 of the left fore-arm, near the carpus, on the 30th of July 1846. It continued for more 

 than a minute to bury its fangs deeper in the flesh, and on quitting its hold voluntarily a 

 little blood flowed from the wounded part, near which a puncture was made simultaneously 

 with a fine needle. The air was sultry, the temperature at the time being 75°, and distant 

 thunder was heard. No difference was perceptible between the results of this and the 

 preceding experiment. 



At ll h 30 m a.m. on the 22nd of August 1846, the thermometer at the time indicating a 

 temperature of 65°, a powerful and much-irritated female Epeira quadrata bit me on the 

 inner side of the left fore-arm, near the carpus. It retained its hold for the space of five 

 minutes, occasionally forcing its fangs deeper into the flesh, and on quitting it voluntarily 

 blood issued freely from the punctures. Due allowance being made for the strong degree 

 of compression employed by this robust spider, the effects of its bite did not differ mate- 

 rially from those of a wound made near it at the same time with a needle of an average 

 size, the intensity and duration of the pain being very similar in both instances. 



On several occasions, in the month of August 1846, spiders of various species were in- 

 duced, under the influence of excited feelings, to seize a piece of clean window-glass with 

 their fangs, when the transparent fluid which escaped from the small aperture near their 

 extremity was deposited upon it. The application of this fluid to the tongue did not pro- 

 duce any sensible effect on that organ ; but the result was very different when the poison 

 emitted under like circumstances from the sting of the common Wasp, Vespa vulgaris ; 

 the Hive-bee, Apis mellifica; or the Humble-bee, JBombus terrestris, was so applied, a 

 powerfully acrid pungent taste being the immediate consequence. A contrast equally 

 remarkable was evinced when these fluids were transmitted into a recent wound ; that 

 secreted by the insects caused inflammation accompanied by acute pain ; effects, which if 

 produced at all by that secreted by the spiders, were scarcely appreciable. 



The legitimate conclusion deducible from the experiments seems to be, that there is 

 nothing to apprehend from the bite of the most powerful British spiders, even when in- 

 flicted at a moment of extreme irritation and in hot sultry weather, the pain occasioned 

 by it being little, if any, more than is due to the laceration and compression the injured 

 part has sustained. 



The manner in which spiders are affected when pierced by the fangs of animals of their 

 own order demands attention in the next place. 



2. Experiments on Spiders. 

 On the 22nd of July 1846, a male Tegenaria civilis, in a violent struggle with a female 

 of the same species, deeply inserted his fangs near the middle of the dorsal region of her 

 abdomen, and retained his hold for several seconds ; from the punctures thus made a 

 brown fluid issued copiously, and in a few minutes coagulated. The injured spider ap- 

 peared to suffer very little from the severe wounds it had received, as it speedily constructed 

 a small web in the phial in which it was confined, and continued for more than a year to 



