1869.] Notices of Scientific Worhs. 405 



may be used with advantage as indicators of the world of wonders 

 which is to be found in the infinitely minute ; and there is a charm 

 in the variety of the work which will render it valuable as a means 

 of interesting young and intelligent minds in the study of Natural 

 History, 



A Course of Six Lectures on the Chemical Changes of Carhoti. 

 By William Odling, M.B., F.E.S., Fullerian Professor of 

 Chemistry, Eoyal Institution. Keprinted from the ' Chemical 

 News,' with Notes by William Crookes, F.E.S., &c. Long- 

 mans, Green, & Co., 1869. 



For many years it was the custom of the late Professor Faraday to 

 deliver, during the Christmas holidays, a course of lectm-es on some 

 branch of science. These were professedly addressed to children ; 

 but the back seats and galleries of the lecture- theatre were gene- 

 rally crowded with adults, many of them well known in the scien- 

 tific world, drawn thither by the charm of the great philosopher's 

 eloquence and manipulative skill. During the many years that 

 this custom was observed, almost every branch of physical science 

 was thus expounded, and it must always be regarded as a misfor- 

 tune that most of these lectures have passed away without a record. 

 The last two courses which Faraday delivered, namely, those " On 

 the Physical Forces," and " On the Chemical History of a Candle," 

 were fortunately pubhshed by Mr. Crookes in the pages of the 

 * Chemical News,' the words as they fell from the speaker's Hps 

 having been taken down by a skilful shorthand writer. 



For a few years Dr. Tyndall delivered the Christmas Lectures, 

 and we are now glad to find that Dr. Odling, the worthy successor 

 to Faraday in his chemical chair, has followed his predecessor's 

 example in continuing them. As in the former cases, the course of 

 lectures, taken down in shorthand, originaUy appeared in the ' Che- 

 mical News,' and they have now been reprinted from that journal 

 in the form of a handsome volume of 162 pages, with preface and 

 notes. 



The author's arrangement of the subject is most logical, and 

 the manner in which he starts from marble — a brittle solid — and 

 gradually mifolds its chemical history before the audience, is a model 

 for all lecturers on science. Dr. Odling starts with no assumption 

 of knowledge on the part of his audience. Every step taken is the 

 logical sequence of that which pi'eceded it, and whilst explaining 

 the phenomena with all that vivacity of style and clearness of ex- 

 pression for which the lecturer is so distinguished, he does not fail 

 to supplement his explanation by a decisive experiment. He first 

 shows that marble effervesces when an acid is poured on it, this 

 effervescence being due to the liberation of a particular kind of air 



