86 



CHEMISTRY. 



be preserved by the " Chapin Home for the 

 Aged and Infirm," founded by members of 

 his congregation in May, 1869. Dr. Chapin 

 died in New York, December 27th. 



CHEMISTRY. Artificial Diamonds. The 

 most interesting and perhaps the most impor- 

 tant chemical discovery of the year is the pro- 

 duction of crystals of carbon, or " artificial dia- 

 monds," by Mr. J. B. Hannay, F. R. S. E., of 

 Glasgow, Scotland. The discovery grew out 

 of experiments which Mr. Hannay conducted 

 during the fall and winter of 1879-'80, in 

 searching for a solvent of the alkali metals. 

 The inevitable result of all the processes he at- 

 tempted with different liquids and gases was 

 that, when the solvent reached the permanent- 

 ly gaseous state, chemical action ensued. A 

 number of experiments were made with so- 

 dium, potassium and lithium, and the hydro- 

 carbons, but the metals in almost every case 

 combined with the hydrogen, setting the car- 

 bon free. A series of experiments with sodium 

 and paraffine-spirit gave a deposit of very hard 

 scales of carbon. This was the reaction on 

 which the experiments for obtaining crystal- 

 line carbon were built. From his experiments 

 on solution, Mr. Hannay deduced the conclu- 

 sion that, if one body has a solvent action upon 

 another without acting upon it chemically, the 

 solvent action may be increased indefinitely by 

 increasing the temperature and pressure of the 

 solvent; but out of eighty experiments made 

 for producing crystallized carbon, only three 

 were attended with satisfactory results. The 

 first were made with sodium and paraffine- 

 spirit. Although the tubes in which the heat 

 and pressure were applied were of extraor- 

 dinary strength, and sealed as tightly as pos- 

 sible, they nearly all leaked ; some exploded ; 

 in some a deposit of scaly carbon appeared, 

 in others the iron was carbonized ; but none 

 gave any results encouraging to the further 

 pursuit of researches in this direction. Mr. 

 Hannay then reverted to the idea of dissolv- 

 ing carbon in a gaseous menstruum. He con- 

 cluded, from some experiments previously 

 made, that a distillation from bone-oil con- 

 taining nitrogenous bases was the most like- 

 ly substance to yield the solvent. A distil- 

 late of this character was placed in a strong 

 tube with charcoal, and heated for fourteen 

 hours. The gas rushed out with force on 

 opening the tube, and a few bright particles of 

 carbon appeared, differing but little, however, 

 from particles of wood-charcoal. Another ex- 

 periment was made with lithium and a mixture 

 of highly rectified bone-oil and paraffine-spirit, 

 which was heated for fourteen hours, then 

 cooled slowly. On opening the tube, after the 

 outrush of gas, a little liquid was found, and at 

 the upper end of the tube, as it lay in the 

 furnace, a hard, smooth masc, which was re- 

 moved with a chisel. Some hard particles 

 were found in pulverizing this mass, which, on 

 examination, proved to be transparent crystals 

 of carbon, or diamonds. New experiments 



were made with other alkali metals, paraffine- 

 spirit, and bone-oil, but they yielded nothing 

 except the scaly carbon. Even lithium failed 

 in most of the succeeding experiments, but a 

 small quantity of carbon crystals was again 

 obtained in one of them. The purity of the 

 crystals was tested by burning a portion of the 

 carbonaceous deposit in oxygen, with results 

 indicating that their composition was 97'85 per 

 cent, carbon. The remainder was found to be 

 nitrogen, which appeared to be present in 

 chemical combination with carbon. From the 

 fact that no diamond was found when nitro- 

 gen compounds were absent, and from the fact 

 that the mixed carbonaceous product contained 

 nitrogen, Mr. Hannay inclines to the belief 

 that it is by the decomposition of a nitrogenous 

 body; and not the hydro-carbon, that the dia- 

 mond is formed in the reactions he has de- 

 scribed. 



Liquefaction of Czone. The liquefaction of 

 ozone has been effected by MM. P. Hautefeuille 

 and J. Chappuis. Having ascertained that the 

 preparation of a mixture very rich in ozone 

 was a first condition to the further successful 

 study of that substance, these chemists ozon- 

 ized oxygen to a greater extent than had hith- 

 erto been done, by passing the silent electric 

 discharge through oxygen at a low tempera- 

 ture. After being submitted to this process 

 for fifteen minutes, the oxygen was conducted 

 into the capillary tube of a Cailletet's appa- 

 ratus, the temperature of which was kept at 

 23. After a few strokes of the pump the 

 gas in the tube appeared of an azure-blue; 

 as pressure increased the depth of color like- 

 wise increased, until under a pressure of several 

 atmospheres the ozonized oxygen appeared of 

 a dark indigo-blue. The pressure was increased 

 to ninety-five atmospheres, and was then sud- 

 denly removed, when the mist which indicates 

 liquefaction was formed in the tube. The sta- 

 bility of a mixture of oxygen and ozone, rich 

 in ozone, appears to be chiefly dependent on 

 the temperature. If such a mixture be rapidly 

 compressed at ordinary temperatures, a con- 

 siderable amount of heat is evolved and the 

 gas explodes. Ozone, therefore, ranks among 

 the explosive gases. Ozone is much more easily 

 liquefied than oxygen ; the latter must be com- 

 pressed under three hundred atmospheres at 

 about the temperature of 29 before sudden 

 removal of pressure succeeds in producing li- 

 quefaction. 



Atomic Weights. The atomic weight of be- 

 ryllium has long been in doubt in conse- 

 quence of differences in the results of the de- 

 termination of its specific heat. The experi- 

 ments of Professor Emerson Reynolds had 

 seemed to confirm the atomic weight of 9-1 

 commonly assigned to the metal, since they 

 gave a specific heat which, taken in connection 

 with that number, correctly indicated the re- 

 ceived assignment of 5*8 as the atomic heat of 

 the substance. Nilson and Petterson redeter- 

 mined the specific heat of the element in 1878, 



