Retrospective Criticism. 407 



Art. VII. Queries and Anstioers. 



Lathrm^a squamaria. — I have doubts respecting the identity of Hud- 

 son's Lathrae'a squamaria, with that of English Botany and Flora^ &c. 

 Would any of your readers furnish you with a short description of the plant, 

 as it may have occurred to them ? Were this done, some hght might, I sus- 

 pect, be thrown upon the true characters of this plant. — G. E. Smith. 

 Sandgate, Aug. 25. 1828. 



Scientific Work on Insects. — Can you inform me of any introductory 

 work on entomology ? I want more information respecting the classifica- 

 tion, than is to be gathered from the excellent book of Messrs. Kirby 

 and Spence, or any other I have met with. Messrs. Kirby and Spence 

 allege that such a work would be found dry by readers ; but it appears to 

 me as necessary to the student of entomology, as a grammar is to the student 

 of languages. A word or two from you, in the Magazine, might set some 

 competent person upon writing a work of this nature, if, as I suspect, none 

 exists. — T. L. H. August 18. 1828. 



Rise and Fall of the Barometer. — In the Companion to the Almanack^ 

 published under the superintendence of the Society for the Diffusion of 

 Useful Knowledge, it is stated, in describing the barometer, that the cause 

 of the rising and falling of the mercury in the instrument has " long puzzled 

 philosophers ; and many erroneous solutions have been given of the pro- 

 blem. By some, the increase of weight has been supposed to proceed from 

 the quantity of water dissolved in the air ; this is, however, refuted by the 

 simple fact, that when the mercury stands highest, the air is most dry ; and, 

 on the contrary, rain generally occurs when the atmosphere is light." What 

 is meant by the words " most dry ; " is it meant that the air is then freest 

 from water, or do they signify, only, that it is then most desiccating ? An 

 explanation from some of your readers will oblige — X. Y. 



Art. VIII. Retrospective Criticism. 



Too great Humanity to Animals. — Sir, Having, this week, received a curious 

 sort of letter of censure for my too great humanity, I enclose it to you, that 

 you may, if you please, make use of it. It is, perhaps, scarcely deserving of 

 notice ; but, as 1 have understood that you like some discussion upon the 

 various subjects treated in the past Numbers of the Magazine, I thought you 

 might like to insert it; I send it, therefore, with some remarks in answer; 

 but, pray, do not scruple to throw both aside, if you think it better to do so. 



" Madam, — Having read, in the Magazine of Natural History, a com- 

 munication from you, entitled, ' Considerations on Botany, as a Study for 

 Young People,' wherein you recommended its pursuit over the other col- 

 lateral branches, inasmuch as it was not fraught with cruelty, and that, in its 

 prosecution, you are without the fear of inflicting pain. Now, as an expe- 

 rimental physiologist, I should beg to give it as my opinion, that the lower 

 class of animals are not susceptible of the sensation of pain. This seems to 

 be dependent upon the tardiness of their circulating systems, and conse- 

 quent want of nervous energy. First, I should like to state to you, that the 

 common eft can have its tail removed without even being conscious of it. In 

 man, and the vertebratae, the seat of sensation is chiefly found in the brain ; 

 but how different in insects. It is a known fact, that the head of most in- 

 sects can be removed, and the animal possess the power to perform all the 

 functions, save seeing and eating, and ultimately only dies of inanition. I 

 am not at all an advocate for deliberate cruelty, but it seems to me that, 

 on this subject, there exists an unnecessary and false feeling amongst your 

 enchanting sex. A lady can read the account of a cool and deliberate blood- 



