LITERARY NOTICES. 



627 



visible to the audience by means of the ver- 

 tical lantern, so that the processes of de- 

 magnetizing, with all the interesting mo- 

 tions of the needles, were seen projected 

 on a luminous screen, eighteen feet in di- 

 ameter. 



" The lecture itself is a masterly pro- 

 duction, and exhibits the result of much 

 close reading as well as experimental re- 

 search. Quotations are given from earlier 

 writers 011 magnetism, illustrative of the 

 sound knowledge which they possessed; 

 and, as each experiment illustrative of the 

 lecture is described, as well as the apparatus 

 employed in manipulation, the reader is 

 conducted from a consideration of the most 

 ordinary magnetic phenomena presented by 

 bar and electro-magnets to that of the same 

 phenomena evolved from terrestrial mag- 

 netism. A paragraph selected from the 

 closing portion of the lecture will fully sub- 

 stantiate this statement: 'Now we have 

 finished our experiments ; and what have 

 they shown ? I have temporarily magnetized 

 a bar of soft iron, by pointing it toward a 

 pole of our large magnet. I did the same 

 with the bar and the earth. I permanently 

 magnetized an iron bar by directing its 

 length toward the pole of the magnet, and 

 vibrating it with a blow of a hammer. I 

 did the same with a bar, struck when point- 

 ed toward the earth's magnetic pole.. I 

 have shown you the action of a small mag- 

 netic disk on iron filings placed above and 

 around it. You saw the earth produced the 

 same action on the beams of the aurora. I 

 showed you the action of this disk on a 

 freely-suspended magnetic needle, and point- 

 ed out to you the earth's similar action on a 

 dipping-needle carried over its surface. I 

 have evolved a current of electricity from a 

 magnet, by cutting with a closed conductor 

 across those lines in which a magnetic nee- 

 dle, freely suspended, places its length. I 

 did the same with the earth by cutting 

 across those lines which are marked out by 

 the pointing of the dipping-needle. There- 

 fore, what am I authorized to infer ? When 

 the effects are the same, the causes must 

 be the same ; for, according to all the 

 principles of philosophy, and conformably 

 to that universal experience which we call 

 common-sense, like causes produce like 

 effects.' " 



Family Thermometry. A Manual of Ther- 

 mometry for Mothers, Nurses, Hospital- 

 lers, etc., and all who have charge of the 

 Sick and of the Young. By Edward Se- 

 guin*, M. D. Pp. 72. Putnam & Sons. 

 This is a valuable monograph upon an 

 important subject, and is an interesting in- 

 dication both of the progress in medical 

 science, and of the need and possibility of 

 diffusing its benefits among the people. 

 More and more as physiology and pathology 

 advance, are we discerning the fundamental 

 nature of the thermal processes in the living 

 economy. That the animal body is, first of 

 all, a furnace to which the digestive system 

 furnishes fuel, and the respiratory system 

 the agent of combustion, is not a mere cu- 

 rious chemical fact, but it is a central and 

 vital physiological law, which is involved 

 with the whole subject of health and dis- 

 ease, of life and death. It may not be 

 proper to say that heat is life, but it is an 

 essential condition of it, and is unquestion- 

 ably the raw material of it if not life, it is 

 yet transformable into life. But the organ- 

 ism generates its heat and loses it by fixed 

 physical laws, while the whole scheme of its 

 activities depends upon the maintenance of 

 the vital temperature at a given point, the 

 norme of health, which is 98 Fahr. in the 

 Caucasian race. Any deviation from this 

 point is an indication of disturbance and dis- 

 ease. The rise of temperature above the 

 standard involves one class of disturbances ; 

 its fall below, another class. The physician 

 alone can deal with the special complications 

 which arise when the temperature ascends 

 or sinks abnormally, but it is in the power 

 of those not physicians to observe the indi- 

 cations, and thus to determine not only 

 when the medical man should be called, but 

 to furnish him with positive and valuable 

 data for his treatment. The use of the 

 thermometer has become indispensable in 

 intelligent medical practice, but Dr. Seguin 

 has shown that it is equally indispensable 

 to mothers in the intelligent management 

 of their children. The only difficulty is to 

 get them to use it, and to give a little atten- 

 tion to the method of registering the results 

 observed. The ordinary thermometer is 

 badly graduated with reference to this use, 

 and so Dr. Seguin has devised a physiolo- 

 gical thermometer marked in so simple a 

 way that it may be employed by anybody 



