PHYSIOLOGY OF THE NERVOUS SYSTEM. 



72 IF 



next paragraph he enquires whether nerves can 

 establish any communication or consent with 

 each other in their ganglia, and also discusses 

 the use of ganglia, giving his assent, in some 

 degree, lo the doctrine which he assigns to 

 Unzer and Winter!,* that external impressions 

 are capable of being reflected by ganglia as they 

 are reflected in the sensorium commune, and 

 that ganglia are particular centres of seasonal 

 impressions (sensoria particularia). He sup- 

 poses that the action of the heart may be ex- 

 plained in this way through the impressions 

 made by the blood upon its sensitive nerves 

 which are reflected at the ganglia ;f and he con- 

 cludes by admitting it to be probable that besides 

 the sensorium commune which resides in the 

 medulla oblongata, the medulla spinalis, &c., 

 there are sensuria particularia in ganglia and 

 anastomoses of nerves (concatenationibus ner- 

 vorum) in winch external impressions are re- 

 flected, without their reaching the sensorium 

 commune. J 



In the fifth and last chapter Prochaska dis- 

 cusses the animal functions of the nervous 

 system. lie shows that the soul, ens incor- 

 porctc prosapias, uses the nervous system as an 

 instrument, and that, in all animal functions, it 

 is the principium agens et determinant. He 

 describes the principal parts into which the 

 animal functions can be conveniently resolved, 

 as perception, judgment, will, to which may be 

 added imagination and memory. For the ex- 

 ercise of these he lays down that the joint and 

 harmonious action of the mind and brain is 

 necessary, and he assigns to each of them a 



* Unzer, Gundriss eines Lehrgebaudes von der 

 Sinnlichkeit der thierischcn Korper, 1768 ; also, 

 Ertse Grunde einer Physiologic der eigentlichen 

 thierischea Natur thierischer Korper. 1771. Win- 

 ter], Inflammationis nova theoria, Viennae, 1767. 

 1 have not had an opportunity of perusing any of 

 the works of Unzer. They are, indeed, little known 

 in this country, having first appeared at a time 

 when German literature was scarcely at all culti- 

 vated here. The only English medical writer with 

 whom I am acquainted, who has made distinct re- 

 ference to Unzer from having; apparently studied 

 his works, is Sir Alexander Crichton, who seems to 

 have formed a high estimate of Unzer's Erste 

 Grunde einer Physio!, as I gather from his work on 

 Mental Derangement, published in 1798. Dr. Haly, 

 the learned translator of M tiller's Physiology, also 

 refers to Unzer ; and I must express my obligations 

 to an interesting article in Dr. Forbes's journal (the 

 British and Foreign Medical Review) for July, 

 1847, which contains a good abstract of Unzer's 

 views, with an account of his writings. From this 

 it is plain that Unzer had very enlarged views with 

 reference to the phenomena of the nervous system, 

 and perfectly appreciated the distinction to be made 

 between those actions with which the mind is con- 

 cerned either as excitor or recipient, and those 

 which in their causation and developement are 

 wholly independent of the mind, although not un- 

 perceived by it. The publication of Unzer's prin- 

 cipal works and also of Prochaska's in an English 

 dress would be a great boon to the student of the 

 physiology ot the nervous system, and would most 

 legitimately come within the scope of the Sydenham 

 Society. 



f This is the doctrine in most favour at the pre- 

 sent day. 



It is plain from the context that Prochaska had 

 no idf a of these sensoria having any connection with 

 the mind, or with the mental power of perception. 



different locality in the brain. Tn the last sec- 

 tion he again defines the animal actions, and 

 distinguishes them from those which are de- 

 pendent on a physical exciting cause ; and 

 argues against the Stahlian doctrine, which 

 placed each movement and function of the body 

 under the control of the soul. 



These doctrines are repeated and somewhat 

 enlarged upon in a much later work by Pro- 

 chaska, published at Vienna in 1810, entitled, 

 " Lehrsatze aus der Physiologic des Men- 

 schen," a third and much enlarged edition of 

 a text, book for his lectures. The whole section 

 on the nervous system will repay an attentive 

 perusal, and especially the chapter headed 

 " Verrichtung des allgemeinen Sensoriums," 

 which contains a review of the doctrine of re- 

 flex actions. A later edition of the same work, 

 somewhat compressed in some parts, published 

 in 1820, contains a repetition and a distinct 

 enunciation of the same doctrines (p. 92).* 



It is not a little remarkable, and at the same 

 time highly discreditable to physiologists, that 

 views so comprehensive and so striking should 

 have been suffered to fall into neglect and to be- 

 come almost wholly forgotten, and that the pe- 

 culiar power of nervous centres to develope 

 motions in response to sensorial impressions, or, 

 in Prochaska's language, " to reflect sensorial 

 into motor impressions," should have been lost 

 sight of. Le Gallois, indeed, had recognized this 

 power, and Blane had evidently much insight 

 into it; Mayo, likewise, had formed a very 

 correct appreciation of it, as shown by his 

 observations on the actions of the iris. But 

 none of these physiologists were fully impressed 

 with its immense importance. It is to Dr. 

 Marshall Hall in this country and to Professor 

 Muller in Germany that science is most in- 

 debted for awakening the attention of physi- 



* Geo. Prochaska was born in 1749, and studied 

 medicine at Vienna, where he was clinical assistant 

 to the celebrated De Haen. He published an in- 

 augural dissertation de minis, but the works which 

 first attracted notice were his Quaestioncs Physiolo- 

 gies, Vienna, 1778 ; and his treatises De Carne 

 Musculari, and De Strtictura Nervorum. In 1778 

 he was made professor of anatomy and of ophthal- 

 mic surgery at the University ol Prague, where he 

 formed a valuable cabinet of preparations of mor- 

 bid parts. In 1791 he was translated to a similar 

 chair in the University of Vienna, with the title of 

 Lehrer der hohern Anatomie, Physiologic-, und 

 Augenarzneykunde. M. Dezeimetis, from whose 

 Dictionnaire Histonque de la Medecine (art. Pro- 

 chaska) this account is abridged, remarks of him 

 that " he was one of those who strove to reduce 

 the laws of life to the general laws of nature, and 

 to make physiology a branch of experimental phy- 

 sics." Prochaska died on the 17th of July, 1820. 

 The works in which he propounded his views re- 

 specting the nervous system are, 1. Annotation. 

 Academic, fasc. iii., Prague, 1784. 2. Lehrsatze 

 aus der Physiol. des Menschen, 1st ed., 1797, in 

 2 vol.; 2nd ed. 1802; 3rd ed. 1810. 3. Opera 

 minora Physiologic! et Pathologici Argument!, 

 p. i. et ii. 4. Physiologic oder he lire von der Na- 

 tur des Menschen, 1820. To these, perhaps, may 

 be added a Latin edition of his Physiology, Insti- 

 tutioncs Physiologic Hnmanar, 1805-6; and I)i<q. 

 Anatoin. Phys. Organismi Corporis Humani, ejusq. 

 Processus Vitalis, 1812; but neither of these works 

 have I seen. 



