72 



SCIENCE. 



[Vol. V., No. 103, 



gathered in the same middle cretaceous strata 

 of ' western Kansas ' referred to a moment 

 ago. 



Prized more highly than even these, how- 

 ever, are the hundreds of skeletons, or parts 

 of skeletons, of gigantic walking and swimming 

 reptiles, herbivorous and carnivorous, which 

 inhabited the cretaceous ocean, and basked 

 upon the shores of the islands of that age, now 

 forming the heights of the Rockies. 



Among the earliest were disclosed wonder- 

 fully preserved bones of the class of mosasau- 

 roicl reptiles, — a group, which, though rare in 

 Europe, here attained an enormous develop- 

 ment, both in numbers and in variety of forms. 

 Nearly seventeen hundred individuals, of this 

 kind of giant-reptile alone, stand on the mu- 

 seum's catalogue. 



The land-forms were even more terrible to 

 the imagination, though their food was vege- 

 table, and their disposition probably peaceful. 

 One such sauropodan dinosaur shown to the 

 public was sixty feet in length, and in general 

 form came nearer to a crocodile than any thing 

 else. A thigh-bone, lying in an exhibition 

 case, measures six feet in length and is solid ; 

 so that it was well able to support the weight 

 of the monster as it rose, kangaroo-fashion, 

 on its hind -legs, to browse its food or to look 

 about it. 



In another colossal reptile (Apatosaurus) of 

 nearly equal proportions, one of the neck- 

 vertebrae is shown which is three and a half 

 feet in diameter ; while the ponderous bones of 

 Brontosaurus prove, that, when living, the ani- 

 mal must have weighed twenty tons or more. 

 The smallest part of it is the head ; the skull 

 and brain being more diminutive, in proportion, 

 than in the case of any other animal now 

 known. It had no weapons of offence or de- 

 fence, nor even any armor ; but in another 

 genus (Stegosaurus) approaching it in bulk, 

 though of more compact form, the body was 

 protected by massive plates, and armed with 

 long spines. This exaggeration of a cross 

 between a snapping-turtle and a hedge-hog 

 possessed a singularity in structure, since in 

 one of the vertebrae of the haunch is a large 

 nerve-cavit3 T , which contained a second or 

 posterior brain, supplementing the extraor- 

 dinarily small nerve-centre in the skull. This 

 feature has no parallel in the animal kingdom. 



To Professor Marsh's personal collection 

 somewhat has been added at the museum hy 

 the U.S. geological survey, which will become 

 the publisher of the outcome of his studies 

 now in progress. A score or so of assistants 

 are constantly on dut} T , either in studj T , or in the 



mechanical work of skilfully extracting fossils 

 from the rocl^y matrix ; in matching and mount- 

 ing by the aid of wire, clay, and plaster, for 

 permanent preservation, the often badly broken 

 bones of some antique brute whose extinction 

 most of the world can accept with resignation ; 

 or in making casts, models, and drawings of 

 fossils, original and ; restored.' 



Several quarto volumes are alread} T under 

 way ; and scarcely an issue of the American 

 journal of science appears, without an advance 

 note of some special discovery in vertebrate 

 paleontology, anticipating the completer de- 

 scriptions to be made from this museum's rich 

 materials. Ernest Ingersoll. 



RIVER-POLLUTION IN ENGLAND. 



After a delay which is much to be regretted, the 

 English government has printed the reports left by 

 Dr. Angus Smith on the working of the Alkali-works 

 regulation act and the Rivers-pollution prevention act. 

 As we mentioned at the time of Dr. Smith's death, 

 he attached great importance to his examination of 

 polluted waters. Great improvements have been 

 effected in lessening the injurious vapors from chemi- 

 cal works. The new works registered are engaged 

 chiefly in the manufacture of sulphate of ammonia 

 and chemical manure. The smaller gas-works have 

 found that they can more profitably manufacture and 

 sell sulphate of ammonia than send their gas-liquor 

 to a distance. The directions in which improvements 

 have latterly been most marked have been in the 

 treatment of sulphuretted hydrogen evolved in the 

 manufacture of sulphate of ammonia, and in the wash- 

 ing of the gases evolved in the treatment of coprolites 

 and other materials at the chemical works. In the 

 former case, oxide-of-iron purifiers have been erected 

 as the best means of preventing the escape of sul- 

 phuretted hydrogen; and in some works this gas is 

 now completely burned, instead of being allowed to 

 escape unhurnt, up the chimney, as formerly. At 

 others, Claus's method of burning so as to form sul- 

 phur, which is collected, and not sulphurous acid, 

 has been adopted. Dr. Smith maintains, that, what- 

 ever process be used, the limit of sulphurous acid 

 allowed to escape should not exceed five-tenths of a 

 grain per cubic foot, including the acidity of the coal- 

 smoke itself, which latter varies from a quarter to 

 half a grain. The escapes from sulphuric-acid works 

 have been considerably reduced, in consequence of 

 the introduction of regular testing by manufacturers ; 

 and condensers to absorb the nitrous fumes have 

 been put up in a number of nitric-acid works. 



Dr. Smith's new method of testing with sugar the 

 amount of organic activity amongst the microbes (at 

 least, of a certain class) which exist in waters was 

 mentioned nearly a year ago in the technical journals. 

 He found that in nearly all natural waters sugar fer- 

 ments, and hydrogen gas is then given off. So far as 



