Notices respecting New Books^ 219 



gives an account of the discovery that two pieces of canes rubbed 

 together gave a faint light, which he shows was occasioned by the 

 sihca contained in the epidermis. In the same letter he announces 

 a more important fact — " I made a discovery yesterday, which 

 proves how necessary it is to repeat experiments. The gaseous 

 oxide of azote is perfectly respirable when pure. It is never dele- 

 terious but when it contains nitrous gas. 1 have found a mode of 

 obtaining it pure, and I breathed to-day, in the presence of Dr. 

 Beddoes and some others, sixteen quarts of it for near seven 

 minutes. It appears to support life longer than even oxygen gas, 

 and absolutely intoxicated me. Pure oxygen gas produced no al- 

 teration in my pulse, nor any other material effect ; whereas this 

 gas raised my pulse upwards of twenty strokes, made me dance 

 about the laboratory like a madman, and has kept my spirits in a 

 glow ever since. Is not this a proof of the truth of my theory of 

 respiration ? for this gas contains more light in proportion to its 

 oxygen than any other, and I hope it will prove a most valuable 

 medicine." 



In the year 1800, appeared in one octavo volume, ' Researches, 

 Chemical and Philosophical ; chiefly concerning Nitrous Oxide, or 

 Dephlogisticated Nitrous Air and its Respiration. By Humphry 

 Davy, Superintendant of the Medical Pneumatic Institution.' — This 

 is a work containing the results of great labour and numerous ex- 

 periments. Dr. Paris remarks that " it may perhaps appear ex- 

 traordinary to the reader of the ' Researches,' that although they 

 were published not more than eighteen months after the appearance 

 of his ' Essays on Heat and Light,' no allusion is made in them 

 either to his theory, or his new nomenclature. In relating his ex- 

 periments upon respiration, he employs the conventional language 

 of the schools, and the word * phos-oxygen' does not once occur 

 in the volume. This is fully explained in a communication made 

 by him to Mr. Nicholson, and which was printed in his Journal a 

 short time after the publication of his Essays in the West Country 

 Contributions; in which he says, 'As facts have occurred to me 

 with regard to the decomposition of bodies, which I had supposed 

 to contain light, without any luminous appearance, I beg to be con- 

 sidered as a sceptic with respect to my own particular theory of 

 the combinations of light, until 1 shall have satisfactorily explained 

 these anomalies by fresh experiments. On account of this scepti- 

 cism, and for other reasons, I shall in future use the common 

 nomenclature; excepting that, as my discoveries concerning the 

 gaseous oxide would render it highly improper to call a principle, 

 which in one of its combinations is capable of being absorbed by 

 venous blood, and of increa^ing the powers of life, uzole,—\ shall 

 name it, with Dr. Pearson, Chaptal and others, Nitkogene; and 

 the gaseous oxide of azote I shall call Nitrous Oxide." 



" There is one circumstance connected with the views enter- 

 tained in this work," observes Dr. Paris, " which must not be passed 

 over without notice. In several passages he advocates the theory 

 of the ataio pherc being a chemical compound of o.xygen and nitro- 



2 V 2 gen ; 



