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THE POPULAR SCIENCE MONTHLY. 



tion by the access of too much blood to such 

 a degree as to weaken or nullify the anaes- 

 thetic influence. Since by this method the 

 anaesthesia can be practically prolonged to 

 an indefinite degree, repeated injections are 

 no longer necessary for that purpose, and 

 the object is attained by the use of com- 

 paratively small quantities of cocaine. Hence 

 the danger of constitutional disturbances 

 from overdosing is avoided. Dr. M. J. Rob- 

 erts has applied the method suggested by 

 Dr. Corning in operations occurring in his 

 practice, with complete success, in cases of 

 excavation of the condyles of the humerus ; 

 of an operation on the bones of the leg ; 

 and of excision of the hip-joint. In the 

 last case the success was less perfect, on 

 account of the operator having been obliged 

 to use a solution of inferior strength, but 

 was fairly satisfactory. Professor J. Willis- 

 ton and other surgeons of eminence have 

 also used the method with complete suc- 

 cess. 



LiTing Encrinites. — The encrinites are 

 among the most interesting of the animals 

 that inhabit the great sea-depths. They 

 formerly played very important parts among 

 the marine fauna, and their remains are 

 found in great masses in the rocks of all the 

 earlier formations. Their shapes, always 

 graceful, now resembling lilies, now palm- 

 trees, were wonderfully varied during the 

 primary and secondary periods. They were 

 nearly always fixed to the ground, while, 

 in modern seas, the echinoderms most like 

 them, the Comatxdw, are free, and have 

 forms resembling star-fish, but lighter and 

 more elegant. Encrinites were regarded as 

 extinct till in the middle of the ei^'hteenth 

 century a naval officer brought to Europe a 

 specimen which had been fished up alive. 

 A few years afterward, Guettard described 

 to the French Academy of Sciences another 

 specimen which, dried, is still preserved in 

 the collection of the Museum of Natural 

 History ; and, at a later date, some encri- 

 nites from the Antilles were distributed 

 among different museums and collections in 

 Europe. But these animals were rare till 

 the time of the American dredging expe- 

 ditions under Louis Agassiz. It is now 

 known that encrinites, while they are not so 

 abundant as they were in the epoch when 



limestone-beds were formed out of them, are 

 by no means rare in the deep seas; and 

 zoologists are in a position to tell geologists 

 what manner of life they lived, and what 

 was the structure of those organisms whose 

 remains are found everywhere, and whose 

 real character once appeared so hard to 

 determine. The discoveries of Sars, in the 

 northern seas, of Pourtales and Alexander 

 Agassiz in the Antilles, and of the various 

 English expeditions, have raised the number 

 of known species of crinoids to thirty-two, 

 whicli are divided among four families and 

 six genera. 



Geology at the imerican Issoeiation. 



— Professor Orton delivered an opening 

 address in the Geological Section of the 

 American Association, on " Problems in 

 the Study of Coal ; with a Sketch of Re- 

 cent Progress in Geology." The recent 

 discoveries of the pteraspidian type of 

 fishes in the Onondaga group of Central 

 Pennsylvania, and of scales and spines of 

 fishes {Onchus Clintoni) in the iron sand- 

 stone of the Middle Clinton group of the 

 same region, give to American formations 

 the earliest examples of vertebrate life yet 

 known. A living shark has been identified 

 that proves to be so nearly allied to the Cla- 

 dodus of carboniferous time that it would 

 be doing but little violence to refer it to 

 that genus. Three separate discoveries of 

 Upper Silurian scorpions and a Middle Silu- 

 rian cockroach carry the life of the earliest 

 land animals a few steps further back than 

 the records of the strata had before dis- 

 closed. Two species of pulmoniferous mol- 

 lusks from the lower part of the carbonif- 

 erous rocks of Nevada constitute the sole 

 known representatives of that group in pa- 

 laeozoic time. Stratigraphical geology ap- 

 pears to be attaining a somewhat juster rec- 

 ognition than has hitherto prevailed ; and 

 the growing use of the microscope in geol- 

 ogy is to be noted as one of the directions 

 in which progress is apparent and marked. 

 In the later stages and higher forms of ver- 

 tebrate life, " American geology holds an 

 easy and undisputed pre-eminence. Along 

 the eastern slopes of the Rocky Mountains 

 there are being disentombed the remnants 

 of great faunas of cretaceous and tertiary 

 time that are quite without parallel in the 



