CRITICAL NOTICES OF NEW PUBLICATIONS. 161 



the study of natural history are manifest. One of its moi^ conspi- 

 cuous merits, and that upon which the immortal Cuvier dwelt, is 

 its tendency to methodise the mind, by impressing it with a habit 

 of order and precision ; thus having all the effect, but under a more 

 alluring mask, of the abstract mathematics, and the logic of the 

 schools." 



The concluding number treats on insects in relation to other or- 

 ganic beings, and contains a well digested history of the chief ento- 

 mological classifications and systems of the several writers in this 

 department of science. 



The Equilibrium of Population and Sustenance demonstrated : an 

 Essay shewing, on physiological and statistical grounds, the means 

 of obviating the fears of the late Mr. Malthus and his followers 

 By C Loudon, M. D. 8vo. London ; and Leamington. 1836. 



Dr. Loudon has opened a new and curious inquiry in this essay ; 

 and when his principle and its proofs shall come to be rightly un- 

 derstood and properly applied, its operation will greatly facilitate 

 the exercise of a pure philanthropy, while its results will conduce 

 progressively and effectually to the diffusion of human happiness. 

 One of the doctor's propositions is remarkable ; but it is founded on 

 a large induction of facts. It is this, that in states where mothers 

 adopt the unnatural practice of not suckling their own offspring, or 

 of continuing this salutary and delightful office only for a short 

 time, there the numerical growth of population is excessive, and, as 

 the shift of a barbarous expediency, too often becomes a cause of 

 infanticide ; and that in countries where mothers prolong the self- 

 rewarding duty of suckling their children for many months or for 

 years, there the population is naturally limited, and nearly station- 

 ary, notwithstanding the inhabitants may possess the necessaries of 

 life in abundance, and of easy acquisition. We solicit Dr. Loudon 

 to prosecute the investigation of his most important subject, until, 

 by evidence and illustration, he has completely established the truth 

 and practicability of his doctrine. At the same time, we would 

 strongly urge the study of this doctrine upon the attention of all 

 those influential and benevolent persons who considerately recognize 

 a solemn and responsible obligation in promoting the welfare of 

 their laborious and virtuous brethren^ We would also very earnestly 

 enforce upon their more fortunate compatriots the pleasure as well 

 as the necessity of endeavouring, by method and kindness, to con- 

 vince this — the laborious and virtuous — order of the people, which 

 has ever constituted the strength and the pride of nations, that vast 

 additions to their comfort and respectability might be derived from 

 such an instructed acquaintance with Dr. Loudon's principle, as 

 would enable them judiciously to determine the fittest occasions and 

 degrees of its requisite applications. 



VOL. IV. — NO. XV. 



