INTRODUCTION. 13 



from his figures given in table 1, the smaller the child the larger was 

 the heat-production per kilogram of body-weight. The author points 

 out, however, that if the heat-production and body-surface are com- 

 pared, as is done in table 2, the uniformity is remarkable. He gives a 

 very unsatisfactory explanation of his unit of surface, but brings out 

 the fundamental idea that the heat per unit of body-surface is essentially 

 the same for an infant as for an adult weighing G5 kilograms, namely, 

 14 to 17 calories. No information is given regarding the muscular 

 activity, the age, or the pulse-rate of these infants. 



In another paper, Langlois 1 refers to Richet's observations on normal 

 children weighing from 7 to 10 kilograms with a heat-production of 

 approximately 4,000 calories per kilogram per hour, and reports his own 

 results with sick infants in which he finds a direct relationship between 

 the body-temperature and heat-production. Infants having temper- 

 atures below 37.5° C, which he takes as normal, had a heat-production 

 less than 4 calories per kilogram of body-weight per hour, while those 

 with temperatures above 37.5° Chad a higher heat-production; thus, 

 with a body-temperature of 35.5° C, the heat-production was equal to 

 2,900 calories, while with a body-temperature of 40.5° C, it was equal 

 to 4,600 calories. 



Langlois's calorimeter was subsequently used by Variot and Saint- 

 Albin 2 in studying the calorimetry of atrophic infants. The tests of 

 this calorimeter published by Saint- Albin 3 show a possible error of plus 

 or minus 10 per cent, thus indicating that the apparatus can hardly be 

 considered an instrument of precision. As Saint-Albin himself points 

 out, his check tests differ considerably from those of Langlois. 



Variot and Saint-Albin studied a large number of atrophic infants; 

 their conclusions, reported by Saint-Albin, are especially interesting in 

 connection with this report of our researches, as they show that (using 

 their terminology) out of 33 atrophic infants, there were 11 "hyperray- 

 onnants," 16 "hyporayonnants," and 6 "rayonnants normalement." 4 



Of the numerous forms of calorimeters reported to the French scien- 

 tific societies by d'Arsonval, one 5 was employed by Bonniot 6 in 1898 for 

 a study of the heat-production of infants with temperature disturb- 

 ances, but he found no regular relationship between heat radiation and 

 rectal temperature. A detailed presentation of Bonniot's results may 

 be found in his thesis for 1900. 7 



langlois, Compt. rend., 1887, 104, p. 860. 



2 Variot and Saint-Albin, Bull, de la Soc. de Pediatre. 1903. 5, pp. 246 and 307. See, also, an 

 extensive discussion of these researches in the thesis by Saint-Albin, Etude sur la calorimetrie des 

 infants atrophiques, Paris, 1904, No. 295. 



3 Saint-Albin, loc. cit., p. 25. *Ibid., p. 39. 



6 See note on this particular calorimeter by d'Arsonval, Mem. de la Soc. de Biol., 1898, p. 248. 



6 Bonniot, Mem. de la Soc. de Biol., 1898, p. 249. For a critique of the Richet and d'Arsonval 

 calorimeters, see Bonniot, Calorimetrie infantile. Etat de la question. Clinique Infantile, 1906, 

 4, p. 289. 



7 Bonniot, De l'hyperthermie dans la fievre; essai de calorimetrie clinique, Paris, 1900, No. 419. 



