VOL. L.] PHILOSOPHICAL TRANSACTIONS. 229 



the windings of the tubes. He thought to have found them again ; but it was a 

 difficult task to search for them. He crushed them, or they were themselves 

 mashed in the tubes, which he pressed, and of which he had consequently 

 spoiled the texture ; but he could not find them ; and this happened several 

 times. These worms have no particular lodge : they crawl indifferently in the 

 tubular labyrinth. So that without offence to Pliny and other naturalists, he 

 does not see that it is in their power to dilate and contract the bodies of the 

 sponges ; which always remain in the same state of magnitude, without being 

 any way sensible to the touch, or any other motion of the sea, nor to any other 

 accident whatever, being an inanimate body ; for the animal sensitive life, or 

 whatever you will have it, belongs only to the worms, that form these bodies, 

 and which are their dwelling places; and which, by the juice they deposit, make 

 the sponge increase or grow, as bees, wasps, and especially the wood-lice of Ame- 

 rica, increase their nests or cells. In short, the blood or humours, which the 

 ancients have observed, is no other than the mucilage or juice of the substance 

 of these worms. 



LXXIX. Of an Experiment, by zvhich it appears that Salt of Steel does not 

 enter the Lacteal Vessels. By Edward JVright, M.D. p. 594. 



Though iron is universally allowed to be one of the most powerful medicines 

 now in use, yet many physicians observing that the faeces of patients who used 

 it, either in a metallic or saline form, were tinged of a black colour, have been 

 led to think, that in a metallic state it could not be reduced into particles fine 

 enough to be received by the lacteal vessels ; and if taken in a saline form, that 

 it underwent a precipitation in the intestines, by which, being reduced to an 

 earth or calx, it was in like manner rendered incapable of making its way into 

 the blood. But the accurate experiments with which Signor Menghini has fa- 

 voured the public in the Memoirs of the Bononian Academy, sufficiently prove, 

 that the ore and filings of iron, finely levigated, enter the blood in considerable 

 quantity ; as does also the crocus, calx, or earthy part of the metal, though in 

 less proportion than the 2 former, which were found to act with a violent stimu- 

 lus on the vessels, and to have dissolved and broken the crasis of the blood of 

 different animals, that had used them for some weeks in large doses mixed with 

 their ordinary food. Though it must be allowed that these experiments are very 

 curious, yet the subject seems to require a further inquiry, viz. whether iron is 

 capable of entering the blood in a state of solution, or under a saline form : for^ 

 from the violent stimulus, as well as from the dissolution of the blood, and other 

 symptoms brought on by the use of the ore and filings, these substances, not 

 being properly dissolved, appear to have acted in a manner so grossly mechani- 

 cal, that whatever Signor Menghini might think, very little was to be concluded 



