Makch 10, 1899.] 



SCIENCE. 



349 



Still another source of danger arises from 

 the production and use in laboratories, and, 

 frequently in common life, of chemical sub- 

 stances which are explosive per se, though not 

 generally recognized as such, and we have 

 records of accidents, among others, from 

 bleaching powder,* from erythryl nitrate, 

 which has lately come into use in the treat- 

 ment of Angina Pectoris,f from ammonia 

 nitrate, :]; and there are many others, such as 

 the organic nitrates, § nitroso compounds, || 

 diazo bodies,^! diamides,** hydrozoic acid 

 and its derivatives, ff hydroxylamines, JJ 

 chlorates,§§ carbonyl compounds,|||| per- 

 manganates, ^^ peroxides,*** chloridesff j 

 and iodides, III occurring iu the laboratories 

 and used to a varying extent in the arts that 

 are so unstable as to give rise to serious acci- 

 dents if incautiously handled. We may no- 

 tice that so well known a compound as the 

 eupric ammonium nitrate, a body which is 

 often formed in the course of analysis, was 

 deemed by Nobel to possess such value as 

 an explosive that he took out patents for 

 its use in blasting. 



The liquid state conduces more particu- 

 larly to accidents taking place since bodies 

 in this state are liable to escape from their 

 receptacles and to be found in unexpected 

 places. If combustible, when mingled with 

 the atmosphere or when saturating oxidiz- 

 ing agents they burn with extreme rapidity 



* Kept. H. M. Insp. Exp. pg. 47 ; 1897. 

 t Kept. H. M. Insp. Exp. pg. 50 ; 1898. 

 t J. Chem. Soc. 683 ; 1882. 



I Compt rend 109, 92-95 ; 1889. 



II Conip. rend 108, S57-S59 ; 1889. 

 f Annalen 121, 257 ; 1860. 



** J. Prk. Chem. 30, 27 : 107. 

 tt Bericht. 23, 3023 ; 1890. 



jjRec. d. trav. Chim. Pays Bas 10, 101; 1891, 

 and J. Chem. Soc. 54, 435 ; 1888. 

 I J Compte rend. 105, SIS; 1887. 

 nil Bericht. 18, 1S33 ; 1885. 

 Hj. Chem. Soc 54, 330; 188S. 

 *"* Compte rend. 106, 100; 1888. 

 ttt Bull. Soc. Chim. 50, 635-638. 

 IH J. Chem. Soc. 56, 766; 1889. 



and produce very violent effects. When 

 such liquids give off vapors at the ordinary 

 temperatures, or those prevailing during use, 

 the danger is very materially increased, as 

 such vapors are more vagrant and, through 

 diffusion, readily mingle with the atmos- 

 phere. These properties are especially 

 characteristic of many of the products ob- 

 tained from coal tar and from petroleum, 

 bodies whose cheapness, abundance and 

 special adaptability have led to their ex- 

 tended use for domestic heating and light- 

 ing and for many purposes in the arts, but 

 which have, because of this widespread use 

 and in consequence of their possessing the 

 properties named, been the cause of an 

 enormous number of casualties. Dr. C. F. 

 Chandler* showed that much of the danger 

 attending the use of these oils in lamps 

 could be avoided by the elimination of 

 the parafiBnes of low boiling points, and 

 though not the pioneer, yet largely through 

 his active efforts and the agitation which 

 followed them, this principle has properly 

 become widely embodied in legislation. 

 This view as to the source of danger was 

 confirmed by the experiments of Newbury 

 and Cutter, j who found that all the par- 

 afBnes below uonane formed explosive mix- 

 tures with air at the ordinary temperatures, 

 notwithstanding that the boiling point of 

 octane is 124°C. , and that the limit of a safe 

 oil as fixed by the ' flashing test ' defined 

 by the New York State statutes is reached 

 only in decane. Yet this last-named com- 

 pound formed a violently explosive mixture 

 at the legal flashing temperature if but a 

 small quantity of the liquid was placed in 

 the copper testing vessel, thus indicating 

 that entire safety is not assured in its use 

 and that accidents might occur when it 

 is used in lamps so constructed that the oil 

 chamber becomes highly heated. Dewar| 



* Petroleum as an IllumiDator ; Kept. N. Y. City 

 Board of Health for 1870. 



t Am. Chem. J. 10, 356-363 ; 1888. 

 t Eept. H. M. Insp. Exp. 21, 55; 1897. 



