SENNEFELDER SENSES. 



195 



student of jurisprudence ; but, after his father's 

 death (1791), he attempted a theatrical career. 

 Not succeeding in this, he became an author, though 

 his poverty prevented him from publishing his j 

 works. He tried many plans with copper-plates 

 and compositions, as substitutes for letter-press, in 

 order to be his own printer. He found, in the 

 course of his experiments, that a composition of 

 soap, wax and lamp-black, formed a good material 

 for writing on his plates ; that, when dry, it became 

 firm and solid, and that it resisted aquafortis. 

 Wanting facility in writing backwards on the plates, 

 he got some pieces of Kilheim stone, as cheap 

 materials on which he could practise after polishing 

 their surfaces. One day, being desired, by his 

 mother, to take an account of some linen about to 

 be sent to be washed, and having no paper at hand, 

 he wrote the account on a polished stone, with his 

 composition ink, intending to copy it at his leisure. 

 When he was afterwards about to efface this writ- 

 ing, it occurred to him that he might obtain impres- ; 

 sions from it; and having eaten away the stone 

 with acid for about the hundredth part of an inch, 

 he found that he could charge the lines with print- j 

 ing ink, and take successive impressions. This new 

 mode of printing appeared to him very important, j 

 and he persevered through all difficulties in apply- ' 

 ing his discovery to practical purposes, and in im- ' 

 proving it. In the course of many experiments, he 

 found that it was not necessary to have the letters j 

 raised above the surface of the stone, but that the 

 chemical principles by which grease and water are 

 kept from uniting, were alone sufficient for his pur- 

 pose. This point obtained, lithography may be 

 said to have been fully discovered. All that was 

 required was the improvement of the materials, and 

 the mode of working with them, and the construc- 

 tion of a proper press for taking the impressions. 

 The perseverance with which he followed up his 

 experiments, in order to overcome the difficulties 

 which successively arose in his progress, was re- 

 markable, and the more so, considering the want of 

 method in his proceedings. Often did he waste 

 months in surmounting a difficulty which a little 

 knowledge, or a very little reasoning, would have 

 enabled him to conquer immediately. The first 

 essays to print for publication, were some pieces of 

 music, executed in 1796 ; afterwards he attempted 

 drawings and writings. The difficulty he had in 

 writing backwards led him to the process of trans- 

 fer ; and the use of dry soap, which was found to 

 leave permanent traces, which would give impres- 

 sions, naturally led to the mode of chalk drawings. 

 Having made considerable improvements, Mr Senne- 

 felder obtained, in 1799, a patent privilege for 

 Bavaria, when he made known his process, and af- 

 terwards entered into partnership with Mr Andre, 

 of Offenbach, who proposed to establish presses, 

 and take out patents in London, Paris and Vienna. 

 For this purpose Sennefelder went to London with 

 a brother of Andre's ; and, the invention having 

 been much spoken of, under the name of polyauto- 

 graphy, most of the principal English artists made 

 trials of it. Unfortunately, however, the art of 

 printing from the stones was not then fully under- 

 stood, and the difference between the materials of 

 Germany and those of England, used both for the 

 purposes of drawing and printing, caused constant 

 failures ; and the artists, in succession, abandoned 

 the practice of it. In August, 1800, Sennefelder, 

 who had separated from Andre, went to Vienna, 

 where, after much difficulty, a patent was obtained, 



and extensive preparations were made for applying 

 his process to print cottons; but bad management, 

 and some unfortunate circumstances, prevented his 

 success, and he returned to Munich in 1806, leaving 

 the establishment in other hands. Mr Mitterer, 

 professor of drawing at the public school of Munich, 

 now (1806) practised lithography to multiply copies 

 for the pupils, and is said to have invented the 

 chalk composition in its present form, or, at least, 

 to have improved it greatly. From this period, the 

 practice of the art has extended and improved 

 rapidly, and more particularly at Munich, where 

 several establishments were formed, for the purpose 

 of applying it to the fine arts, as well as for print- 

 ing writings and official forms, for the different de- 

 partments of the government. In October, 1809, 

 Sennefelder was appointed inspector of the royal 

 lithographic establishment at Munich, for printing, 

 from stone, a complete map and survey of Bavaria; 

 since which period he devoted his time to experi- 

 ments, and to writing the history of his invention. 

 (See Lithography.) In 1819, Sennefelder publish- 

 ed his Elements of Lithography (in German). In 

 1826, he invented a new process for taking impres- 

 sions on coloured sheets, so as to imitate oil-paint- 

 ing. This art he called mosaic printing. He died 

 at Munich, 26th February, 1834. 



SENSES. The internal organs of the five senses 

 seeing, hearing, feeling, smelling and tasting are 

 the nerves, small, thread-like fibres, distributed all 

 over the body, and all connected with the brain. 

 (See Nerves.) Few subjects, in comparative 

 anatomy and physiology, have given rise to more 

 various and contradictory opinions than the exter- 

 nal organs of sense in some classes. Much misun- 

 derstanding on this point has arisen from the hasty 

 application of inferences drawn from the human 

 subject to other animals. Thus it has been sup- 

 posed that those which possess a tongue must have 

 it for the purpose of tasting, and that the sense of 

 smell must be wanting where we are unable to trace 

 the existence of a nose. But, in many instances, the 

 tongue cannot, from its substance and mechanism, 

 be considered as an organ of taste, and must be 

 merely subservient to the ingestion and deglutition of 

 food ; while in many animals, particularly insects, an 

 acute sense of smell seems to exist, although no part 

 can be pointed out in the head which analogy would 

 justify us in describing as the nose. The sense of 

 touch appears to exist only in four classes of animals, 

 in most mammalia, in a few birds, in serpents, 

 and probably in insects ; and although all animals 

 may possess that feeling which makes them sensible 

 to the impressions of warmth and cold, very few 

 possess, like the human subject, organs exclusively 

 appropriated to the sense of touch, and expressly 

 constructed for the purpose of feeling, examining 

 and explcring the qualities of external objects. 

 (See Touch.} The sense of taste, as we have 

 above remarked, does not appear to be confined to 

 the tongue, that member being wanting in many 

 animals which do not seem destitute of the sense ; 

 and in many which possess it, the tongue is em- 

 ployed for other and different purposes. (See 

 Taste.) The sense of smelling prevails much more 

 extensively in the animal kingdom than that of 

 taste, since it not only assists several genera in 

 selecting their food, which they have not afterwards 

 the power of tasting, but is also of service in find- 

 ing out proper objects for the satisfaction of their 

 sexual appetites. (See Smell.) We should na- 

 turally expect to find an organ of hearing in most 

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