268 ANNUAL OF SCIENTIFIC DISCOVERY. 



of the two experiments do not compensate one another, the error of 

 the method cannot exceed a tenth of a miligramme. 



The author then instituted experiments to test this method. From 

 these it appeared that distilled water to which a known quantity of 

 ammonia had been added, furnished more ammonia than had been 

 mixed with it ; so that, apparently, all distilled water contains ammo- 

 nia. The water employed in the following experiments was distilled 

 first with sulphate of alumina, and afterwards over potash, to remove 

 any ammonia and carbonic acid that might be contained in it. In the 

 following table the first column gives the number of the experiment, 

 the second the quantity of ammonia added to the water, the third the 

 quantity obtained from the distillate, and the fourth the difference be- 

 tween the two preceding : 



I. II. III. IV. 



1. 0.01233 0-01224 0-00009 



2. 0-00036 0-00037 -4-0-00001 



3. 0-01056 0-01040 0-00016 



4. 0-01130 0-01131 -f-0-00001 



5. 0-00836 0-00840 -[-40000.0 



6. 0-04944 0-04950 -f-0-00006 



7. 0-00413 0-00410 0-00003 



The quantity of ammonia found in a cubic meter of water taken 

 from various wells and rivers of France, varies from 0-03 of a gramme 

 to 0-73 of a gramme. In one instance, the quantity found in a river- 

 water, adjacent to several manufacturing establishments, was 2.61 

 grammes, other waters examined yielded no traces of ammonia. In a 

 litre of sea-water from near Dieppe, M. Boussingault found 0.00020 

 grammes of ammonia. If we consider that two-thirds of the surface 

 of the globe are covered with water, the sea always contains a consid- 

 erable quantity of ammonia, which may return again into the atmos- 

 phere. In places where great numbers of persons live, the quantity 

 of ammonia in the soil increases. In the rain-water collected in Paris, 

 Baral found on an average 3.35 milligrammes of ammonia to one litre 

 of water. The greatest quantity he met with was 5.45 milligrammes. 

 Boussingault's determinations thus far agree well with Burral's. Thus 

 in the first week in April he found 4.34 milligrammes in litre of rain 

 water at Paris. This was twenty-seven times as much as existed at 

 the same time in the Seine water. 



OIL OF HOPS. 



Wagner has recently published some researches on this body. It 

 does not contain sulphur and belongs to the hydrocarbons of the group 

 6 10 H 8 . This oil is but slightly soluble in water. It has no narcotic 

 action. When pure it is of a light brown color, has a powerful but 

 not intoxicating odor, a warm and bitter taste, resembling thyme. It 

 scarcely reddens litmus , paper. It appears to be isomeric with the 

 oil of bergamot and the aldehyle of camphodic acid. By treating 



