270 Notices respecting New Books. 



part with fidelity, and in a way creditable to himself. Tt 

 is of much more importance than mere operative mechanics 

 can possibly conceive, that the best form of the teeth of 

 wheels should be ascertained on true mathematical princi- 

 ples. Where this is not attended to, there will always be an 

 mmecessary load on the machinery, arising from mere fric- 

 tion, a consequent waste of power and time, and a propor- 

 tionate expenditure for repairs. We cannot however avoid 

 noticing that there is a manifest disagreement between the 

 text of this work, and an illustration of the application of the 

 epicycloid to the teeth of wheels given in the preface. The 

 latter directs the epicycloid curve to be generated from the 

 primitive diameters of the wheels that are to work into each 

 other; the former directs them to be generated from circles 

 equal to radius only of these diameters. — ^This work, we 

 doubt not, will be found very useful, and we hope will 

 procure to the publisher a proper return for the service he 

 has rendered to the public by presenting it in an English 

 dress. 



T/ie Vaccine Contest ; or *•' Mild Humanity, Reason, Reli- 

 gion, and Truth, against fierce unfeeling Ferocity, over' 

 hearing Influence, mortified Pride, false Faith, and De- 

 speration," &c. By William Blair, M. A. Surgeon 

 of the Lock Hospital, Mc. &c. Puhlislied by Murray. 

 In this work, designed for the use of clergymen, heads of 

 families, and other unprofessional readers, Mr. Blair at- 

 tempts to answer the objectors against the cow-pox, on 

 quite a new plan ; viz. by quoting their own words, and 

 making them refute themselves; in which it is but justice 

 to say, he has effectually succeeded. This popular work i* 

 a very fair exposure of the unprincipled mean? to which the 

 anti-vaccinators have resorted to turn the prejudices of the 

 ignorant into a source of dishonest emolument to them- 

 selves. 



Doctor Patterson, of Londonderry, strongly impressed 

 •with the importance of the subject, is engaged in *' Re- 

 searches concerning Pestilential and Epidemic DiseaseSj 

 4 with 



