RELATIONS OF ANIMAL HEAT TO RESPIRATION. 427 



by earlier writers. The most remarkable of these was Mayow, 

 who, in 1667, and afterward in 1674, published a work on 

 the Spiritua Nitro-aereus, and on respiration, in which he 

 attributed to the nitro-aereous gas (oxygen) the property of 

 combining with the blood in the lungs, producing the red 

 color, and generating heat. 1 These ideas, as well as those 

 advanced by Crawford, near the time of the publication of 

 the first observations of Lavoisier, were crude and indefinite, 

 and contributed but little to our positive knowledge of the 

 mechanism of calorification. 2 



It will not be necessary to treat, from a purely historical 

 point of view, of the discoveries made by Lavoisier, as this 

 has already been done sufficiently under the head of respi- 

 ration. 3 He undoubtedly went as far in his explanations of 

 the phenomena of animal heat as was possible in the condi- 

 tion of the science at the time. his investigations were made; 

 and although he inevitably fell into some errors in his calcu- 

 lations and deductions, he must forever be regarded as the 

 -author of the first reasonable theory of the generation of 

 heat by animals. 



The Consumption of Oxygen and Production of Car- 

 bonic Acid in Connection with the Evolution of Heat. As 

 far as it has been possible to determine by actual experiment, 



1 MAYOW, Tradatiis quinque Jfedico-physici. Quorum primus agit de Salnitro, 

 et Spiritu Nitro-aereo. Secundus de Respiratione, etc., Oxonii, 1674, p. 151, et seq. 

 The first edition of the work on Respiration was published in 1767. 



2 CRAWFORD, Experiments and Observations on Animal ffeat, London, 1788, 

 second edition, p. 354, et seq. Crawford published the first edition of his work 

 in 1779, but the second edition, in which his views are avowedly made to cor- 

 respond with the observations of Lavoisier, is the only one at all accessible. 

 From all we can learn of the matter contained in the first edition, from extracts 

 and references in other treatises, Crawford's ideas were not in advance of those 

 presented by Lavoisier to the Academy of Sciences, in 1777. 



3 The various papers published by Lavoisier and Seguin, and Lavoisier and de 

 la Place, are scattered through the volumes of memoirs of the French Academy 

 of Sciences, from ITTTto 1790. An exhaustive analytical review of these memoirs 

 is given by Gavarret (De la chaleur produite par les etres vivants, Paris, 1855, p. 

 165, et seq.). 



