266 



SCIENCE, 



[N. S. Vol. IX. No. 216. 



NOTES ON INORGANIC CHEBIISTBY. 



Further studies of hydrozoic acid, HNg, are 

 given in the Journal fur prakiische Chemie by 

 Professor Curtius and Dr. Rissom. All of its 

 salts as far as known are anhydrous. Lithium 

 hydrazoate explodes violently on heating, and 

 thallium hydrozoate detonates by percussion ; 

 the other hydrazoates of the alkalies and alka- 

 line earths are comparatively stable. When 

 they are heated carefully in small quantities in 

 thin glass tubes they decompose quietly with 

 evolution of nitrogen and the metal is left in a 

 pure condition. This is pointed out as being 

 the easiest method of preparing small quantities 

 of barium, strontium and calcium. In the 

 light of Moissan's recent researches, it would 

 be interesting to know if the residual substance 

 on heating calcium hydi-ozoateis really metallic 

 calcium, or calcium nitrid, which might read- 

 ily be formed under these circumstances. The 

 authors further find that a solution of the free 

 hydrozoic acid decomposes to some extent on 

 heating with dilute mineral acids, hence the 

 amount of free acid obtained in this way from 

 the salts is much less than the theoretical. 



An interesting synthesis from acetylene has 

 been accomplished by Berthelot, according to 

 the Comptes Bendun. Acetylene is led into fum- 

 ing sulfuric acid, and the potassium salt of 

 the acid thus formed is fused for a short time 

 at 200° C. On acidification and distillation, 

 phenol is easily recognized. This synthesis is 

 peculiarly interesting from the fact that it is 

 accomplished at such a low temperature. 



The work of Hantzsch and of others on the re- 

 actions of inorganic salts in other than aqueous 

 solutions, and especially in solutions of non-elec- 

 trolytes, is bearing much fruit in enabling the 

 preparation of new inorganic compounds. 

 Hantzsch has just described, in the Zeitschrijt fur 

 anorganische Chemie, the disulfid of silver AgjSj, 

 corresponding to the recently discovered di- 

 oxid, Ag202. It is readily precipitated from a 

 solution of silver nitrate in benzouitril, on add- 

 ing a solution of sulfur in carbon bisulfld. It is 

 a brown amorphous powder, insoluble in ordi- 

 nary solvents, melts at a fairly high tempera- 

 ture, but rapidly decomposes, and oxidizes with 

 great rapidity in the air when moist or in water. 

 Other solvents, including pyridin, were tried in 



its preparation, but benzouitril was the only 

 one found in which the disulfid could be 

 formed. 



J. L. H. 



ZOOLOGICAL NOTES. 



Peofessoes W. C. Heedman and Rupert 

 Boyce have presented to the Royal Society a 

 further study of Oysters and Diseases (pub- 

 lished in Nature), from which we take the fol- 

 lowing : 



Although we did not find the bacillus typho- 

 sus in any oysters obtained from the sea or from 

 the markets, yet in our experimental oysters 

 inoculated with typhoid we were able to re- 

 cover the organism from the body of the oyster 

 up to the tenth day. We show that the ty- 

 phoid bacillus does not increase in the body or 

 in the tissues of the oyster, and our figures in- 

 dicate that the bacilli perish in the intestine. 



Our experiments showed that the sea-water 

 was inimical to the growth of the typhoid ba- 

 cilli. Although their presence was demonstra- 

 ted in one case on the twenty-first day after 

 addition to the water, still there appeared to be 

 no initial or subsequent multiplication of the 

 bacilli. 



In our experiments in washing infected oys- 

 sters in a stream of clean sea-water the results 

 were definite and uniform ; there was a great 

 diminution or total disappearance of the typhoid 

 bacilli in from one to seven days. 



The colon group of bacilli is frequently found 

 in shell-fish as sold in towns, and especially in 

 the oyster ; but we have no evidence that it oc- 

 curs in mollusca living in pure sea-water. The 

 natural inference that the presence of the colon 

 bacillus invariably indicates sewage contamina- 

 tion must, however, not be considered estab- 

 lished without further investigation. 



The colon group may be separated in two 

 divisions : (1) those giving the typical reactions 

 of the colon bacillus, and (2) those giving cor- 

 responding negative reactions, and so approach- 

 ing the typhoid type ; but in no case was an 

 organism giving all the reactions of the B. 

 typhosus isolated. It ought to be remembered, 

 however, that our samples of oysters, although 

 of various kinds and from different sources, 

 were in no case, so far as we are aware, derived 



