VOL. LVII.] PHILOSOPHICAL TRANSACTIONS. 36Q 



numbed, because in each of these circumstances, this nervous juice abounds and 

 regurgitates, if he might so speak. 



But these violent motions, whence have they their origin ? there must be a 

 nervous juice, to act in the muscles, and here we have very little. Neither of 

 these animals was deprived of the medulla spinalis, and one of them had a small 

 portion of brain, or cerebellum. This is one source of the nervous juice, and 

 of the active fluid, necessary to muscular motion. This source, he grants, is 

 weak and poor, but he had made it appear in his treatise on this subject, that 

 there is in the blood a richer store, which the nervous fluid unites to, and makes 

 use of, in muscular motion. By this it is explained, how it happens that an ass, 

 which has so much less brains than a man, is yet so much stronger, because it 

 has much more blood. Here then is a 2d spring thai affords these monsters a 

 considerable supply; but though sufficient for their motions, it is not equal to 

 that of an ordinary foetus, and the violent agitations of their body arise from 

 their great sensibility, which we have just now accounted for. Now the blood in 

 the foetus, and especially in these, belongs to the mother; they are furnished by 

 her, as well with air as with the nervous juice, and the animal fluid, which are 

 essential to her. Therefore as soon as these children are separated from the 

 mother, and deprived of that vital source, all motion must cease in them, as if 

 they were suffocated, that is, as in any other suffocated foetus. 



Mr. le C. concludes with a word or two on the cause of these monsters. The 

 great quantity of waters voided by the mothers of these children, proves that the 

 principle of their monstrocity is a disease, a sort of dropsy, and even a kind of 

 h3drocephalus, which had run off" a considerable time before the labour. The 

 2 hydatides he found at the origin of the brachial nerves, and which had evi- 

 dently been the cause of the mutilation of the upper extremities, are examples 

 that help us to comprehend that of the other organs. On supposing a like dis- 

 order on the origin of other nerves, which have their rise from the brain, it will 

 be obvious that the organs to which these nerves run, that is, where they convey 

 the nervous fluid, which contain the rudiments of every part, will be wanting. 

 It may indeed be said, there are hydrocephali that have all the organs very well 

 formed: but there the disease has commenced after the perfect formation of these 

 parts; whereas if you suppose it to have happened in the very time of that for- 

 mation, you will see that the nervous juice, vitiated, diluted, and turned out of 

 its natural course, can no longer be employed in the generation of those organs. 



//. yi Description of Three Substances mentioned by the Arabian Physicians, in a 

 Paper sent from Aleppo, and translated from the Arabic, by Mr. J. Canning, 

 apothecary, p. 21. 

 The Tabashir, Mamithsa, and Mamiraan are used by the Arabian physicians; 



VOL. XII. 3 B 



