VOL. XXVII.] PHILOSOPHICAL TRANSACTIONS. 547 



always been thought troublesome and dangerous, on account of its venom : but 

 I can assure you, that spiders are not venomous, having been very often bitten 

 by them myself, without any ill consequence. And as for their silk, it is so 

 far from having any venom, that every body makes use of it to stop bleeding 

 ?ind heal cuts.; and indeed its natural gluten is a kind of balsam, that cures 

 small wounds, by defending them from the air. 



Their silk is useful, not only in respect of the manufacture it produces ; but 

 its usefulness is much greater, and more essential, on account of the specific 

 medicines, that may be drawn from it. It yields by distillation a large quantity 

 of spirit and volatile salt; and I have found by comparing, that it affords at 

 least as much as common silk, which of all mixed bodies yields the most. This 

 salt and volatile spirit, which is drawn from spider bags, is very active ; as may 

 be judged by the following experiments. It changes the tincture of the flowers 

 of turnsole into a beautiful green emerald colour : it congeals, and reduces 

 to a sort of snow, the solution of corrosive sublimate ; whereas the volatile 

 alcalis, drawn from the human skull, hartshorn, and some other mixed bodies, 

 only render it white or milky. So that this new alkali, being prepared after 

 the same manner as that which is drawn from the bags of silk-worms, in making 

 the English drops, so famous over all Europe, may serve to make other new 

 drops, which may deservedly be called drops of Montpellier ; which we need 

 not scruple to make use of, with much greater success than the old ones, in 

 apoplexies, lethargies, and all soporous diseases, by reason of their great 

 activity : and they will be taken with less reluctance, as their smell is less fetid 

 and disagreeable. 



Plate 12, fig. 13, shows the belly of a spider, with the anus and five papillae, 

 from whence the threads issue. Fig. 14, 15, the side, and fore-part of the 

 penis of a spider, as magnified by a microscope. Fig. l6, the follicle or bag 

 of a field-spider, with a harder shell, at the breaking of which the young 

 spiders come out mixed with the silk. Fig. 17, the follicle or bag of a house- 

 spider, with a softer shell, in which the young ones are inclosed. Fig. J 8, a 

 spider hanging on the branch of a tree, with its head turned against the wind, 

 and spinning out its thread, until it finds that it adheres to some body, by which 

 kind of bridge it passes over rivers, &c. Fig. IQ, a spider having broken the 

 first thread, by which it hung, and let out several others, is carried by the wind, 

 and floats in the air with its legs extended. 



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