504 



SCIENCE 



[N. S. Vol. XLI. No. 1057 



cites experiments which would stand compari- 

 son with those carried out in modern labora- 

 tories, especially those tabulated from WiUiam 

 Watson's series of 1768, in which it is seen 

 that Jenner did not initiate experimental re- 

 search upon the subject but rather devised or 

 followed lines already established before him. 

 The most scientific worker in the field was 

 Angelo Gatti of Pisa, who obtained permission 

 to inoculate in Paris by the rational method 

 of puncture and preparation in 1Y69. Gatti 

 maintained that smallpox is always caused by 

 the introduction into the body of a foreign 

 body, which is in the nature of a specific virus 

 in that it reproduces itself and multiplies, 

 the disease being communicated by contact, 

 inhalation or ingestion. He waxed furious 

 against the senseless practise of weakening the 

 patient by bleeding and purging, adopted 

 Sutton's open-air and hydropathic regime, and 

 offered prizes in real money for any authenti- 

 cated case of reinfection after inoculation. 

 Such cases he regarded as eruptions from a 

 mixed infection of other exanthems, such as 

 scarlatina or measles, which he also thought 

 capable of transference by inoculation. The 

 main difficulty with variolation was that each 

 inoculated person was a possible " carrier " of 

 the disease, and this occasioned Gatti and his 

 associates considerable trouble in Paris. In 

 the meantime, Tronehin, Tissot, Mead and 

 other eminent physicians were influential in 

 spreading the practise, which became a common 

 preventive measure in America during the 

 Revolutionary War. In 1768, Thomas Dims- 

 dale was invited to St. Petersburg to inoculate 

 Catherine the Great and her son, receiving 

 for his trouble a barony, $50,000 down, an 

 annuity of $2,500, $10,000 for his expenses and 

 handsome gifts of diamonds and furs. Jenner's 

 experiments of 1796-8 soon swept variolation 

 from the field, for the sufficient reason that 

 there was little mortality and no possibility of 

 transference of the disease by the vaccinated 

 person. Variolation was declared a felony by 

 Act of Parliament in 1840. 



Dr. Klebs's memoir is well worthy of peru- 

 sal by all who are interested in the history of 

 preventive inoculation. Its permanent value 

 is that it obviates the boresome necessity of 



investigating the huge literature of variola- 

 tion, covering even the secular memoirs of 

 eighteenth century celebrities. Its engaging 

 style makes it eminently readable, revealing 

 everywhere the spirit of its genial author. 



F. H. Garrison 

 Army Medical Museum 



A Primer on Alternating Currents. By W. G. 



Rhodes. Longmans, Green & Company. 



1912. Pp. 145. 



Although this book, according to the author, 

 is primarily intended for students preparing 

 for the alternating current part of the ordi- 

 nary grade examination in electrical engineer- 

 ing of the city and guilds of London, it should 

 be useful to those desiring a very brief ele- 

 mentary course on alternating currents and 

 alternating current machinery. The book is 

 primarily adapted to the use of evening classes 

 in technical schools, and is written in such a 

 way that no knowledge of mathematics is re- 

 quired beyond the elements of algebra. In 

 order to avoid the necessity for the students in 

 these classes to possess a multiplicity of books, 

 such simple mathematical relations as are 

 necessary for the development of the subject 

 are proved in the first chapter of the book. 

 For a similar reason, some useful constants 

 and a short table of logarithms are given. 



The early chapters of the book are devoted to 

 developing the elementary principles of mag- 

 netism, induction and alternating currents. 

 Alternating currents in circuits containing 

 inductance and capacity are briefly considered. 

 The rest of the book deals with transformers, 

 synchronous motors, induction motors and 

 rotary converters. In this part of the book use 

 is made of simple vector diagrams. At the end 

 of the book a few pages are given to the ele- 

 mentary principles underlying transmission of 

 electrical energy and to simple power measure- 

 ments. The usefulness of the book is increased 

 by the addition of a number of examples with 

 answers which are given at the end of each 

 chapter. 



This little book is well adapted for the pur- 

 pose for which it is intended. One should 

 expect to flnd in its 145 pages more than a 

 most brief and elementary treatment of the 



