315 



netic Force," that M. Kreil is of opinion that the observations of 

 different years at Milan and Prague, when combined, would rather 

 favour the contrary inference, viz. that the decennial inequality exists 

 in the lunar as well as in the solar variations. The author was led 

 therefore to re-examine this question by the aid of the observations 

 of the Declination at the Hobarton Observatory, which he considers 

 to be remarkably well suited for the purpose, as they comprise eight 

 years of consecutive hourly observation with unchanged instruments 

 and a uniform system of observation, and number, exclusive of 

 Sundays, Christmas-days, and Good Fridays, and occasional but very 

 rare omissions, no less than 51,998 observations. 



These observations have been examined by the processes already 

 described in the author's communication of last Session, and the 

 results form the subject of the present paper, showing, in the author's 

 belief, decided and systematic evidence of the existence of the diurnal 

 inequality, having its minimum epoch in 1843-1844, and its maximum 

 epoch five years later, in the mean diurnal variation due to the dis- 

 turbances and in the more regular and ordinary solar-diurnal varia- 

 tion, and the absence of any trace of a similar inequality in the 

 lunar-diurnal variation. 



The Society then adjourned over the Christmas holidays, to 

 January 8, 1857. 



January 8, 1857. 



WILLIAM ROBERT GROVE, Esq., V.P., in the Chair. 

 The following communications were read : 



1. "On the Function of the Thyroid Body." By PETER MARTYN, 

 Esq., M.D. Lond., Surgeon R.N. Communicated by Pro- 

 fessor HENFREY, F.R.S. Received November 13, 1856. 



(Abstract.) 



After referring to the form, situation, connexions and internal 

 structure of the thyroid body, its large supply of blood and its capa- 



