130 



and what would have been required before the combustion, gives us 

 one of the elements for calculating the analysis. 



In order to neutralise the acid reaction of one equivalent of the 

 bisulphate, one equivalent of ammonia will be required; therefore 

 127"2 grains of the salt will correspond to 17 grains of ammonia, 

 or to 14 grains of nitrogen. 



I may add, that the high atomic weight of the bisulphate (127' 2) 

 tends to diminish any errors from inaccurate weighing, or the pre- 

 sence of impurities. 



5th, Two comparative analyses of pure uric acid were made at the 

 same time ; 6 grains gave, by Varrentrapp and Will's method, 

 31"90 of the platinum salt, = 33'4 per cent, of nitrogen; theory 

 gives 33"33 ; 5 grains uric acid gave, by the bisulphate process, 

 33'376 per cent, of nitrogen ; theory, 33-333. 



Many other analyses have been made by this process in the Uni- 

 versity laboratory, and with the most satisfactory results, approach- 

 ing in general more closely to the calculated quantities than by the 

 method with bichloride of platinum. 



It is obvious that the bisulphate of potash may be employed with 

 advantage as a substitute for sulphuric acid in common alkalimetry, 

 since it is easier to prepare a solution of the anhydrous bisulphate of 

 any given strength than to obtain a standai'd dilute sulphuric acid. 



2. An account of some Experiments on the Diet of Prisoners. 

 By Professor Christison. 



From careful experiments made, under direction of the Board of 

 Directors of Prisons in Scotland, on 1624 prisoners confined in eight 

 of the principal prisons, for pei-iods not exceeding sixty days ; and 

 from an analysis of numerous observations on their weight and gene- 

 ral health, the author arrives at the following conclusions : — 



1. For the average of people whose occupation involves moderate 

 muscular effort and no great exercise, a simple, well-selected sort of 

 food, supplying seventeen ounces of daily real nutriment, of which 

 four ounces are nitrogenous principles, constitutes a sufficient diet 

 for maintaining health, strength, weight, and general condition ; but 

 less is not sufficient. 



2. The proportion of nitrogenous nutriment in such a diet cannot 



