490 Messrs. G. W. Macdonald and A. M. Kellas. [Mar. 21, 



18. Meckel's ganglion in the embryo is closely connected with the 

 otic ganglion. 



19. The inferior maxillary nerve is at first unbraiiched. 



20. The first formed part of the inferior maxillary represents the 

 inferior dental of the adult. 



21. The lingual nerve is formed later, and is still very small in the 

 fifth week. 



22. Meckel's cartilage presents a close relation to the branches of 

 the inferior maxillary nerve, and seems to determine the directions 

 which they take. 



23. All the important branches of the inferior maxillary nerve are 

 represented in the embryo at the beginning of the sixth week. 



24. At the beginning of the sixth week the otic and submaxillary 

 ganglia are present. 



25. The chorda-tympani, the Vidian, and the nerve of Jacobson 

 are not branches of the fifth nerve, inasmuch as they are not developed 

 from it. 



26. The chorda-tympani and Yidian nerves are branches of the 

 facial, being developmentally derived from this nerve ; the nerve of 

 Jacobson is in like manner a branch of the glossopharyngeal. 



27. The origin of these nerves in man is precisely similar to that of 

 the corresponding nerves in the rat. 



28. There is 110 direct evidence to prove that the cells of the 

 accessory ganglia of the fifth nerve are derived directly from the cells 

 of the Grasserian ganglion. 



29. The sympathetic associated with the carotid artery in the 

 adult is represented in the embryo by fibres chiefly derived from the 

 trunk ganglion of the vagus nerve. 



X. " Is Argon contained in Vegetable or Animal Substances ? " 

 By GEORGE W. MACDONALD, M.Sc., and ALEX. M. KELLAS, 

 B.Sc. Communicated by Professor WILLIAM RAMSAY, 

 F.R.S. Received March 19, 1895. 



At Professor Ramsay's suggestion, experiments were undertaken 

 to see whether argon could be obtained from nitrogenous vegetables 

 or from animal tissues. 



Method : A few grams of the substance, after drying if necessary, 

 were ground to a fine powder, desiccated at 110 C., until the weight 

 was constant, and a nitrogen estimation performed by Dumas' 

 method. It was supposed that any argon compound would be 

 decomposed, when the argon would come oft' along with the nitrogen. 

 The gas was collected in a nitrometer over well-boiled concentrated 



