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object of this work, the author states in his preface, "is to furnish persons who make an artistic or professional use of the vocal organs with a concise but complete account of those scientific relations of the voice, physical and medical, which are generally only alluded to cursorily, or passed over altogether, in works on elocution and singing." The author gives an historical review of the origin and progress of vocal culture, and considers the relation of sound to the voice, the physical construction of the vocal organs, their physical action, the physiological principles involved, and the hygiene of the voice. Under this latter head he considers the effect on the voice of the use of stimulants and narcotics, the diet, the habits of life, of exercise, etc., and gives some directions for its care and treatment when not in good condition.

the four lectures before the Royal Institution contained in this little volume, Mr. Gordon has undertaken to present such facts in electric induction as go to show what it is, and how it is propagated from the excited to any other body. The question, he says, which for fifty years physicists have been trying to answer, is now, through the experimental and mathematical researches of recent years, in a fair way of being answered, and the object of these lectures has been to present some of the data and reasoning upon which this answer rests. According to him, the present position of science on the subject is, that induction is propagated through space by means of undulations in an ether in a manner similar to light, and all that is at present known points to the ether being the same for both excitations, and the difference of the phenomena being due to differences of vibration. An induced body is in a state of strain which in a good conductor is being constantly relieved, and which in a poor conductor is not so relieved. The lectures, when delivered, were illustrated with a number of delicate experiments, descriptions of which and cuts of the apparatus employed are given in the present volume. The lectures are an excellent example of that clearness and directness of statement by which a naturally abstruse subject is made intelligible and interesting to the lay reader.

are volumes in the "Students' Aids Series," on subjects of technical interest only. In the preface to his volume Dr. Semple states that it is intended to be a companion to his "Aids to Chemistry." A long list of remedies is considered, the doses given following closely those in the "British Pharmacopœia."

In the second of the above volumes, Dr. Hemming considers the questions with which medical men have to be familiar in appearing to testify as experts in cases in law courts, and gives a large amount of information in a compact and concise form.

In "Aids to Anatomy" Dr. Brown has aimed to present the main facts of anatomy in such a way as to be most readily grasped and retained by the student, and to be of value to him in the work of dissection.

year covered by this report completes the tenth of the existence of the observatory, and Mr. Draper gives a summary of its establishment and an account of what has been accomplished in this time. The report states the conditions under which the observatory was begun, gives short abstracts from the reports of each year, describes the different self-recording instruments made and used at the observatory, insists on the desirability of a new observatory, and closes with annual and monthly tables. The report is interesting