414 



NA TURE 



[March 5, 1896 



got tacky, it is dusted over until covered with the barium 

 platino-cyanide, which has been finely powdered. 



Greater distinctness is obtained by this method, insuring, as 

 it does, a thin but compact layer of crystals, unseparated by the 

 fibres of the blotting-paper. J. William Gifford. 



Chard, March i. 



Crush-Conglomerates in Ireland. 



On the sea-coast at Portraine, Co. Dublin, there is an ap" 

 parent thickness of over 700 feet of conglomeratic rocks, which 

 have hitherto been regarded and described as of volcanic origin, 

 contemporaneous with the Lower Silurian strata and associated 

 felspathic igneous rocks. 



This conglomerate is massive in character, and exhibits a 

 structure resembling rude bedding. It consists of sub-angular 

 and rounded blocks and pebbles of grey fossiliferous Bala lime- 

 stone, calcareous grit, and occasional lumps and fragments of 

 crushed felsite, the whole being enveloped in a brownish-grey 

 argillaceous and calcareous matrix. 



The Lower Silurian section here shows grey limestone pass- 

 ing upwards into alternations of grit, limestone, and argillaceous 

 shale, with thick bedded calcareous mudstones at top, the whole 

 series being more or less fossiliferous. 



The associated igneous rocks are intrusive basic felsites of 

 several varieties, and, like the sediments, present evidence of 

 intense crushing. 



Having had assigned to me, in the Geological Survey, the 

 revision of the Silurian tracts in this part of the east of Ire- 

 land, I spent some time on the ground last summer, and was 

 led to form the conclusion that this supposed conglomerate is 

 not of volcanic origin. The work has not yet been officially 

 inspected, but I am enabled, with the sanction of the Director- 

 General, to state here briefly the results at which I have arrived. 



I believe that instead of volcanic detritus contemporaneous 

 with the deposition of the Silurian strata, we have here a vast 

 crush-breccia or crush-conglomerate, formed by the breaking-up 

 both of the Lower Silurian sediments and the igneous rocks, 

 along particular zones of earth-movement, and a flowing and 

 subsequent re-cementing together of the broken-up and rolled 

 fragments. So far as I could judge, there are no truly con- 

 temporaneous igneous rocks in the district. 



Where the intrusive rocks have come within the region of 

 intense squeezing, they are sheared and ground into more or 

 less powdered masses, having a resemblance to volcanic 

 material, and this probably gave rise to the supposition that 

 they were volcanic. 



The breaking-up of the hard bedded rocks can best be 

 studied at the south end of the section, and in some cases the 

 beds of limestone and grit can be seen, as it were, in the process 

 of being broken up into detached pieces, the fragments rolling 

 off through the mudstones. 



The conditions at Portraine are repeated exactly on Lambay 

 Island, three miles off, but apparently on a grander cale. 



I consider this crush-conglomerate rock-structure to be of 

 great importance in connection with many more supposed 

 volcanic areas of Silurian age in Ireland. 



Alex. McHenry. 



Geological Survey Office, Dublin, February 28. 



Science and Morals. 



All who are engaged in extending the boundaries of natural 

 knowledge will be interested in the remarkable letter of Prof. 

 Ramsay, in last week's Nature, on the moral claims of original 

 discoverers in relation to the work of subsequent investigators 

 in the same field of research. As one whose experience is of 

 sufficient duration to stand in both these relations, I should like 

 to point out several objections to the position assumed by Prof. 

 Ramsay on this question. 



In the year 1866 I announced before the Royal Society the 

 discovery that quantities of magnetism and electricity indefinitely 

 small would induce quantities of these forces indefinitely great, 

 and demonstrated the same, on a large scale, by means of a 

 small magneto-electric, acting in conjunction with a large 

 dynamo-electric machine.^ The discovery excited consider- 

 able interest at the time, and my experiments were repeated 

 by many electricians in Europe and America. Among these 

 1 Proc. Roy. Soc, 1866; Phil. Trans., 1867. 



NO. 1375, VOL. 53] 



were Varley, Wheatstone, Siemens of Berlin, and Farmer in 

 America, who soon found that the residual magnetism of an 

 electro-magnet was sufficient to supply the initial current 

 required for exciting the dynamo ; thereby dispensing with the 

 permanent steel magnets of the magneto-electric machine. 

 Although I had actually made experiments in the same direction 

 some time previous to the announcement of my discovery, it 

 never occurred to me, before reading Prof. Ramsay's letter, that 

 I have all these years been a martyr to the injustice inflicted by 

 unscrupulous electricians publishing, without my consent, the 

 happy invention of the self-exciting dynamo machine. 



The work of an original discoverer, though popular, is not 

 unfrequently of a very subordinate character ; increasing, in 

 some cases, the value and importance of previous discoveries, 

 or preparing the way for still greater ones, which the original 

 investigator may be quite unable to deal with. The pretension 

 set up by Prof. Ramsay, with its personal application, that the 

 permission of an original discoverer should be obtained before 

 the results of subsequent researches in the same field by other 

 workers are published, strikes at the root of all scientific pro- 

 gress, and indicates a simplicity of character rarely to be met 

 with in those engaged in philosophical pursuits. 



Prof. Ramsay is again unfortunate in his analogy between the 

 moral questions involved in a scientific discovery and in a 

 patented invention. Law and equity alike encourage the 

 publication of subsequent improvements on original inventions 

 without the consent of the first inventor, and only intervene and 

 censure when the right and title to his own invention are 

 impugned. 



The morality of Prof. Ramsay would suppress all investi- 

 gations on the RiJntgen rays, now being made wherever 

 science is cultivated, or would render it impossible for the 

 original discoverer to consider the numerous applications for 

 permission to publish the results of further experiments. 



The policy of secrecy and procrastination suggested as a 

 corrective to the activities of subsequent investigators is not 

 likely to meet with the approval of scientific men who have in 

 mind the history of the discovery of the planet Neptune, and the 

 rival claims of Adams and Leverrier. A great master of science 

 (Sir George B. Airy) has well said with reference to this and other 

 discoveries, ' ' that it is advantageous for the progress of science 

 that the publication of results, when so far matured as to leave 

 no doubt of their general accuracy, should not be delayed till 

 they are worked to the highest imaginable perfection." 



February 25. Henry Wilde. 



Inverted Images. 



In connection with the view advocated by Mrs. Scott in your 

 last number, it may be of interest to state that, in my own 

 personal case, I have been able all my life to read a book with 

 the greatest facility upside down ; it making not the least 

 difference to me which way it is presented. I am told — but this 

 is not within my personal recollection — that I learned to read by 

 looking over the book of an elder brother who was being taught 

 in the usual way, standing in front of him, not behind. The 

 singular circumstance to my own mind is that I have precisely 

 the same facility in reading upside-down books written in any 

 foreign language with which I may be more or less acquainted, 

 in which the letters differ from the English, as Greek and 

 Hebrew ; and the facility extends, to very nearly the same 

 extent, to handwriting. I have never at any time practised it 

 systematically ; it appears to come perfectly naturally. 



Alfred W. Bennett. 



Remarkable Sounds. 



A peculiar sound, apparently similar to the "soughing of 

 the wind " (see p. 78, ante), is briefly described by Liu Wan- 

 Ping, a Chinese Commodore, in his journal of voyage made in 

 1595 from Cheh-Kiang to Shan-Tung, in order to defend the 

 latter province from the attack by the Japanese fleet. (Sie 

 Tsai-Kang's " Wu-tsah-tsu," Japanese edition, torn. iv. 

 fol. 46, a.) The passage is as follows: "Same night we 

 anchored near Fuh-shan-tau [in Shan-Tung]. This mountain, 

 as if inhabited by a deity, utters a voice sounding mournfully, 

 although on it neither herb nor tree exists, and neither hollow 

 nor cavern therein." KuMAGUSU Minakata. 



February 8. 



