SCIENCE. 



173 



II. Observations at Sea. 



Under this head three distinct investigations have been 

 made, as follows ; 



(a.) From an examination of the results obtained by 

 chronometric longitude expeditions, we find that for a 

 voyage of 15 days the average error is 5.3 s ; the range 

 between the greatest and the least results in each series is 

 18.0 s ; the latter value has a range between 1.5 s and 

 55.0 s , and the coefficient is 3.4. 



(3.) The longitudes of 36 stations have been determined 

 by various British naval expeditions. The chronometers 

 were rated at the Greenwich Observatory before starting, 

 and the observations for time at the terminal stations 

 were made in the usual way with the sextant. Evidently 

 more than usual care was taken both with the observations 

 and reductions. We find that the average difference be- 

 tween the results obtained by different chronometers is 

 4.4 miles with a range of 1 5.1 miles. The average range 

 between the different results for longitude is 5.0 miles 

 with a range of 31.6 miles. The average number of 

 chronometers was 11, and the average duration of voyage 

 was 11 days. 



(c.) During the spring and summer of 1880 Officer W. 

 H. Bacon, of theCunard steamer " Scythia," kindly under- 

 took for me a series of systematic observations from 

 which the relative errors could be determined with con- 

 siderable certainty. A complete series for a single day 

 consisted of five sights at intervals of fifteen minutes, 

 about 8 o'clock in the morning, five sights in the neigh- 

 borhood of 1 1 o'clock, and five sights at the corresponding 

 hours in the afternoon. Observations were also made 

 when the ship was in known positions as often as pos- 

 sible. 



This series of observations has an exceptional value 

 on account of the conscientious fidelity with which the 

 programme was adhered to and of the skill with which 

 they were made. The ralative errors were determined by 

 comparing each position with the mean of the series, the 

 rate being determined both from the morning and after- 

 noon observations and from the log. 



The results obtained are found in the following table : 



Limits in 

 Miles. 



Average Error 

 from Observations 

 at g 1 ' and 3''. 



Average Error from 

 Log at 9 11 and 3 h . 



Average Error 

 from Observations 

 at n 1 ' and i 1 '. 



Average Error from 

 Log at 1 1 ,l and i h . 



Difference between 

 Observation and Log 

 at 9 1 ' and 3 1 '. 



Difference between 

 Observation and Log 

 at n h and iK 





No. 



No. 



No. 



No. 



No. 



No. 





Cases. 



Cases. 



Cases. 



Cases. 



Cases. 



Cases. 



0.0- 0.5 



1 













7 



6 



0.5- I.O -- 



9 



6 



2 



3 



1 





1.0- T.5 



8 



13 



3 



5 



3 





1.5- 2.0 



4 



5 



3 



3 



3 



2 





6 



4 



6 . 



5 



2 





2.5- 3-o 



2 



1 



3 



4 









3 0- 3-5 



2 



2 





5 



7 



2 



3-5" 4.o 



4 









1 



2 



4-o- 5-c 



1 



3 



6 



5 



4 



4 



5.0- 6.0 - 











2 



1 



1 



5 













2 



1 



2 



2 



7.0- 8.0 _ 



1 



1 







1 



1 



1 



8.0- 9.0 



2 







1 



1 







2 



9.0-10.0 







1 











I 



2 





















1 



1 



11.0-12.0 



















2 



1 



12,0 + 



1 



1 



















QUERY. 



A SUBSCRIRER would like to know the best method 

 of mounting Triple phosphate crystals (dry) so as to 

 tack them to the slide without interfering with definition. 

 — Replies invited. 



ON THE ACTION OF BACTERIA ON VARIOUS 

 GASES * 

 By F. Hatton. 



The experiments were made to ascertain the nature of 

 the action exerted by various gases on the life and in- 

 crease of bacteria, and to observe what influence the 

 bacteria had on the percentage composition of the gases. 

 The bacteria were obtained by shaking fresh meat with 

 distilled water. The aqueous extract was filtered and 

 exposed to the air for twenty-four to thirty-six hours; it 

 was always found to be full of bacteria. A small flask 

 was half filled with mercury, filled up with the bacteria 

 solution, and inverted in a mercury trough. The gas 

 under examination was then passed up, a small glass 

 vessel was innoduced under the mouth ot the flask, and 

 the whole removed from the trough. The liquid was ex- 

 amined daily as to the condition of the bacteria, the sam- 

 ple being removed by a piece of bent glass tubing hav- 

 ing an india rubber joint. Alter about a week the gas 

 was pumped out by means of a Sprengle and analyzed. 

 Atmospheric air was first tried. The bacteria lived well 

 during the fifteen days cf the experiment (T. 15 to 22°). 

 A large absorption of oxygen took place, but it was not 

 replaced by carbonic anhydride ; in a second experiment 

 (T. 25 to 26^50) 20 per cent, of the oxygen disappeared, 

 and only 17 per cent, of C0 2 was formed. Pure hydro- 

 gen after fourteen days had no action on the bacteria ; 

 the gas contained 0.34 per cent. C0 2 , 98.94 per cent. H. 

 Pure oxygen after ten days was converted into C0 2 29.98 

 per cent., O 70.02 per cent. A mixture of CO 46.94 per 

 cent., COi 1.27, O 1.27, N 50.51, was next tried after four- 

 teen days ; the gas contained C0 2 17-77, CO 0.55, H 7.58, 

 CH 4 2.50, N 71.57. In all of the above cases the bacteria 

 flourished well. Cyanogen was next tried. The solution 

 of meat turned gradually to a thick black fluid. On the 

 fifth day very few bacteria could be seen. From this 

 time, however, they increased, and on the twelfth day 

 were comparatively numerous. On the fifteenth day the 

 gas was analyzed ; it contained CN 5.35, C0 2 57.59, O 

 2.24, N 34.79 ; a second experiment gave similar results. 

 It appears, therefore, that cyanogen is fatal to bacteria as 

 long as it exists as such, but that it soon decomposes in- 

 to ammonic oxalate, &c, and that the bacteria then re- 

 vive, especially in sunlight. Sulphurous anhydride was 

 next tried ; the bacteria lived during the fifteen days : the 

 gas contained C0 2 7.87, O 0.00, N 2.13, S0 2 90.10. Sim- 

 ilar results were obtained with nitrogen, nitrous oxide, 

 nitric oxide, carbonic anhydride, a mixture of H and O 

 obtained by the electrolysis of water and coal gas. 

 In all cases the bacteria lived well during the exper- 

 ment. The author next experimented with a solution of 

 urea (0.98 per cent.) and phosphate of potash (0.4 per 

 cent.), sowing it with bacteria. The bacteria lived well 

 during the fourteen days of the experiment ; small quan- 

 tities of gas were evolved containing 0.53 per cent. C0 2 , 

 2.64 per cent. O, and 96.82 per cent. N. An experiment 

 was made with spongy iron, air, and bacteria. On the 

 fourth day, all the bacteria had vanished ; the air was 

 analysed on the fifth day, and consisted of C0 2 0.26, 

 O 0.00, and N 99.74 per cent. Experiments were also 

 made with acetylene, salicylic acid, strychnine (10 per 

 cent.), morphine, narcotine, and brucine ; none of these 

 substances had any effect on the bacteria. On the other 

 hand, phenol, spongy iron, alcohol, and potassium per- 

 manganate were very destructive to these microscopic 

 growths. 



Mr. W. M. Hamlet said that these experiments con- 

 firmed some observations of his own. He had found 

 that bacteria could exist in almost anything — in carbonic 

 oxide, hydrogen, 1 per cent, creosote, phenol, methylamin, 

 methylic alcohol, chloroform. Moreover, Crace-Calvert 

 had shown that they could live in strong carbolic acid. In 



* Read before Chemical Society, March 3, 81. This paper obtained for 

 the author the Frankland Prize of £50 at the Institute of Chemistry. 



