Foreign Literature and Science. 175 



This process will dissolve more copal than the liquid will 

 contain when cold. The most economical method is to put 

 the vessel aside for some days and when the solution is ef- 

 fected, to decant the clear varnish and leave the rest for a 

 second operation. — Ibid. 



24. Pyrolignous acid. — Agreeably to the experiments of 

 Berzelius, detailed in the transactions of the Royal Academy 

 of Sciences at Stockholm, every trace of empyreumatic oil 

 may be removed from this acid by animal charcoal. It is 

 only necessary to mix the charcoal with the acid and fil- 

 ter immediately. The charcoal which remains in the pro- 

 cess of making prussian blue was found to be very efficacious, 

 even in exceedingly small quantities. — Bull. Unit). Juillet, 

 1826. 



25. Crystallization of Camphor, by M. John. — I have ob- 

 served that the vapours of camphor, which are spontaneously 

 developed in the course of a few years in a glass well closed. 

 and containing camphor wrapped in paper, crystallize in 

 small tables with six faces, of which the two which are op- 

 posite are larger than the four other faces. The crystals are 

 transparent and very brilliant. — Bull. Univ. Mars, 1826. 



23. Animal Magnetism. — A volume on this subject enti- 

 tled, Lettres physiologiques et morales sur le magnetism 

 animale, contenant l'expose critique des experiences les plus 

 recentes et une nouvelle theorie sur ses causes, ses phenome- 

 nes et ses applications a la medicine, &c. par J. Amedee 

 Dupau, D. M. 1 vol. 8vo. was published in Paris in 1826, in 

 the form of letters addressed to Professor Alibert. The spirit 

 which has directed the author, in these letters, is that of 

 doubt and examination, the only sure guide to the truths of 

 science. Without troubling himself with vain denomina- 

 tions, M. Dupau has enquired by researches into the mysteries 

 of ancient temples, and the magical secrets of the middle ages, 

 whether all the physical and moral phenomena, which certain 

 practises determined, were not owing to the same cause and 

 belonged not to the same series of facts. The author has 

 sought to demonstrate, not that animal magnetism is no- 

 thing, but that it is a different thing from what the magne- 

 tisers suppose : he shows that magnetic phenomena have ex- 

 isted at all times, and that they present themselves to the ob- 



