24 REPORT OF THE SECRETARY. 



having been made by the Institution for this investigation, it has been 

 found that there is a small discrepancy between the two sets of results, 

 the cause of which has not yet been ascertained. 



If it is found on further examination that there is really a discrepancy 

 between the observations of Uranus and its motion as computed from 

 the theory of gravitation, it will be considered that the chance of the 

 discrepancy being due to an ultra-Neptunian planet is sufficient to jus- 

 tify the continuance of the work. 



Professor Newcomb remarks that the problem now before us is vastly 

 more difficult than that with which Le Terrier had to deal. When Le 

 Terrier had completed the determination of the motions of Uranus, 

 taking into account the action of Neptune, he considered the representa- 

 tion of the observations by theory highly satisfactory. But the out- 

 standing differences were far larger than those with which we are now 

 occupied. 



In regard to the computations of the comet of short period mentioned 

 in the last report, we have nothing further to report at present, the work 

 having been suspended for a time on account of the transfer of Professor 

 Stone from the National Observatory to the Cincinnati observatory, and 

 the consequent absorption of his time in preparing for his new duties. 



A small appropriation has also been made for a series of physiological 

 observations on the temperature of the human body under certain 

 abnormal conditions, by Prof. H. C. Wood, jr., and Dr. Horace Hare, of 

 Philadelphia. These observations are in progress, and it is thought the 

 results of the investigation will be. ready for publication in the next 

 annual report. They relate especially to the subject of animal heat, the 

 mode of its production, and its relation to pathological and normal func- 

 tions. The first question to be investigated is whether ordinary fever 

 is due to* an increased production or retention of heat. A series of 

 analytical experiments as to the amount of carbonic acid given off by 

 the animal during the normal and the febrile state, also the amount of 

 excretions from the kidneys, will be made, and a determination as to 

 whether the depression of temperature, caused by ammonia, section of 

 the spine, injuries, &c, is due to a diminished production or increased 

 loss of heat; also whether the paralytic fever observed in connection with 

 certain nerve sections is always caused by such sections, whether it is 

 induced by an increase in the production of heat, or by its retention ; and 

 finally, how the nervous system acts in the regulation of the calorific 

 function. 



METEOROLOGY. 



The Institution has continued the reduction and discussion of the 

 large amount of meteorological material which it collected during the 

 twenty years of its system of observations. The miscellaneous work by 

 the computers of the Institution during the year 187G, is as follows : 



1. The temperature observations for the years 1871, '72, '73, have been 



