94 



CHEMISTRY. 



ventilate the coal by passing or drawing air into the 

 body of the freight would l>e most likely to favor 

 the production of a highly explosive mixture of gas 

 and air. The only useful application whioh might 

 be made of any special means of ventilation with a 

 view to diminish the risk of explosions would be to 

 pass a current of air over the coal and immediately 

 into the open air, so as to accelerate the escape and 

 removal of the inflammable gas." 



The commissioners briefly discuss the means of 

 extinguishing fire by generating carbonic-acid gas 

 and applying it to the ignited portions of a coal- 

 cargo ; but are of opinion that, as this gas has no 

 cooling effect, it will not be useful in the case of a 

 considerable mass of ignited coal then water and 

 eteam are the only agents available. 



Influence of Fertilizers in Beet- Culture. In 

 the course of their experiments on beet-culture, 

 Deherain and Fr6my planted some beets in 

 absolutely sterile soils, to which were added 

 from time to time such substances as were 

 thought to be essential for the development of 

 the plant. It was found that the beets con- 

 tinued in the rudimentary state when they re- 

 ceived in such soils only distilled water ; they 

 increased slightly in weight when common 

 water took the place of distilled ; their de- 

 velopment was greater still when the water 

 contained soluble phosphates, or salts of pot- 

 ash ; but yet the roots never attained the 

 weight of 100 grammes. When for these min- 

 eral substances were substituted ammoniacal 

 salts or nitrates, the yield was much better. 

 Normal beets, however, cannot be grown un- 

 less to these nitrogenous fertilizers are added 

 phosphates and potash-salts. It is worthy of 

 note that, when the beet finds in the soil ni- 

 trogen, phosphorus, potash, and lime, it de- 

 velops as well as in a soil containing humus. 

 To establish this point Messrs. Deherain and 

 Fr6my compared the produce of two such soils, 

 and found that the beets grown in sterile soil 

 were heavier than those grown in rich soil. 



On examining the beets grown in plots in 

 the experimental garden of the museum, the 

 authors found them to be very poor in sugar, 

 though tho soil was very rich. From this it 

 follows that deficiency of sugar in the beet is 

 not due to exhaustion of the soil. In seeking 

 the true cause, it occurred to Messrs. Deherain 

 and Frerny to ascertain how much nitrogen the 

 beets contained, and found the amount to be 

 very large. Hence it appeared that a soil rich 

 in nitrogenous matters is unfavorable to the 

 production of sugar. This conclusion was con- 

 firmed by sundry analyses of beets grown at 

 the museum, at the school of Grignon, and in 

 the departments of Aisne, Nord, and Eure, 

 All the results positively confirm the observa- 

 tions made by the authors, and their conclusion 

 is. that, if beets are now less rich in sugar than 

 formerly in those departments which have 

 long produced them, that fact is not owing to 

 the exhaustion of the soil and its deprivation 

 of principles necessary for the development of 

 the beet; on the contrary, the reason of the 

 phenomenon is, that the soil is too rich in ni- 

 trogenous matters, in consequence of the lib- 

 eral use of manures. 



Influence of Sewage on the Ground- Atmos- 

 phere. Experiments similar to those of Pet- 

 tenkofer, of Munich, have been made in Boston 

 by Prof. William Ripley Nichols, to determine 

 whether well-constructed sewers have any del- 

 eterious effect on the surrounding ground- 

 atmosphere. For this investigation, the old 

 Koxbury sewer on Dearborn Street was chosen. 

 This sewer was built in 1860, and the bottom 

 is not impervious to water. A pipe was driven 

 into the ground in the neighborhood of the 

 sewer, and the opening of the pipe was calcu- 

 lated to be about one and one-half foot from 

 the sewer, and on a level with the spring 

 of the arch. This would be ten feet from the 

 surface of the street. Examination failed to 

 detect sulphureted hydrogen or marsh -gas. 

 Carbonic-acid determinations were made as 

 follows: 



Numbr of Volumes of Carbonic 

 Acid in 1,000 Volumes of Air. 



October 6th 35.31 



" 18th 134.63 



November 12th 23.46 



The following more complete examinations 

 were made: 



An examination was also made of the air in 

 the ground near the Berkely Street sewer (at 

 the corner of Newbury Street). In this place 

 it was impossible, on account of the water in 

 the ground, to draw the air from a point as 

 close to the sewer as in the previous case. 

 The air was actually taken about nine feet six 

 inches from the surface of the street, and the 

 spring of the arch of this sewer is twelve feet 

 below the level of the street. 



The examination shower* : 



These examinations would seem to indicate 

 that, with the exception of an increased 

 amount of carbonic acid, there is no evidence 

 of the contamination of the ground-atmos- 

 phere by the sewers, and it would seem highly 

 improbable that injurious emanations from un- 

 derground sewers should ever reach the air 

 above by passing through the soil. 



Wearing of Platinum Retorts by Sulphu- 

 ric Acid. In communicating to the Paris 

 Academy of Science the results of his pro- 

 tracted observations on the deterioration of 

 platinum alembics used in concentrating sul- 

 phuric acid, Scheurer-Kestner (American 

 Chemist for February) states that the degree 



