Db. "Watt <m the Laws of Mortality at Different Ages. 1 93 



growth. Specimens of Closterium Digitus, with the starch granules 

 changed into blue by iodine, were exhibited under the microscope. 



Dr. Balfour also exhibited under the microscope specimens of 

 Desmidiacooo and Diatomacesc, and illustrated the paper bj drawings 

 of plants belonging to these orders. 



A communication was then read bj Professor Gordon on the 

 Application of the Calculation of Probabilities in the Formation of 

 Science. 



Sd January, 1844, — The President in the Chair, 



The following statement of the estimated revenue and expenditure 

 for the current year was laid before the Society : — 

 Annual Revenue, exclusive of Entrance Fees, . . £100 

 Surplus of 1842-3, 35 10 



Estimated Expenditure:- 

 By Publications ordered, 

 Publishing Proceedings, 

 Ordinary Expenses, including Rent, 

 Estimated Rent at Martinmas, 



Leaving a Balance of £17 16 2 



The following paper was then read: — 



XLIV. — On the Laws of Mortality at Different Ages. By Alexander 

 Watt, LL.D., City Statist. 



In a paper which was published in the Proceedings of this Society 

 last year, I showed, from the returns obtained from different towns 

 in England and Scotland, that tlie amount of deaths by various 

 diseases is nearly identical at the same ages ; and that whatever the 

 total amount of deaths by each disease may be, the proportion which 

 the deaths falling at certain periods of life bears to the whole deaths 

 by these respective diseases, remains the same. The examples given 

 in that paper related to fever, measles, small -pox, and bowel com- 

 plaints. As the law which was deduced from these examples appeared 

 to be of great interest, it became an important point to determine 

 whether it was of more general application, since a knowledge of the 

 specific laws of mortality by such diseases at different ages, by deter- 

 mining more clearly the nature and operation of the disease, may be 

 expected to lead both to improved modes of medical treatment, and 

 to facilitate the introduction of such sanatory regulations, as would 



