( 618 ) 



XXIII. — On the Quantity of Nitric Acid and Ammonia in Rain- 

 Water. By J. T. Way, 15, Wei beck Street, Cavendish 

 Square, 



It will be in the recollection of the readers of this Journal, that, 

 in the midsummer number for 1856, I published a paper 

 ' On the Composition of the Waters of Land-drainage and of 

 Rain,' in which I gave analyses of the rain-water of each month 

 in the year 1855, collected at Rothamsted, and kindly supplied 

 to me for the purpose by Mr. Lawes. 



In order to save the necessity of reference, I will very briefly 

 state the results of that examination. It should be premised that, 

 up to the time from which the investigation in question dates, the 

 methods in existence for the determination of the very minute 

 quantities of nitric acid and ammonia present in rain-water were 

 of so faulty and incomplete a character, that no reliance could 

 be, or by competent judges was, placed in the few isolated 

 results which had been published on this head ; and opinions 

 on the amount of influence which the nitrogenous elements of 

 rain-water might exercise on vegetation, were loose and specu- 

 lative in the extreme. By the aid of entirely new and highly 

 refined methods of analysis, I was enabled to ascertain with 

 certainty what quantity of nitric acid and ammonia was brought 

 down to the soil by the rain-water of each month in the year 

 1855. It was found generally : — 



1. That the total quantity of nitrogen brought down in the 

 form of rain was much smaller than had been previously 

 supposed, and that it was altogether insufficient to account for 

 the amount of produce obtained naturally in uncultivated and 

 unmanured soils. 



2. That of the nitrogen so brought dbwn by rain, very much 

 the larger proportion existed in the state of ammonia. 



.3. That, as a rule, both the ammonia and nitric acid falling in 

 rain in any one month were in direct proportion to the quantity 

 of such rain, modified only to a certain extent by the number of 

 occasions on which rain had fallen. 



4. That nitric acid was found in the rain of each month of the 

 year, and consequently, if it be the result of electrical action, 

 such action must be continuously in exercise and not confined to 

 special sea^ns. 



Such were the general conclusions which seemed justified by 

 the analysis of the rain-water of different months in the year 

 1855. It seemed desirable that this investigation should be 

 extended over a second year, and accordingly, by the help of 

 Mr. Lawes, who has a second time placed samples at my disposal. 



