president's address. 1219 



disease was mooted so far back as the year 1726. In the English 

 Mechanic of April 1883, the following extracts are given from 

 an old book published in its fifth edition in 1726, and entitled, 

 " New Improvements of Planting and Gardening, both Philoso- 

 phical and Practical," by Richard Bradley, Professor of Botany 

 in the University of Cambridge and F.R.S. 



In the Chapter on Blights of Plants, he says : — " I am very 

 apt to believe that the most epidemical distempers mankind is 

 subject to proceed from poisonous insects, which are either eaten 

 unregarded or sucked into the stomach with the breath, as that 

 worthy gentleman Mr. Batte so curiously observes in a letter I 

 have received from him relating to infectious distempers, which I 

 shall annex to this chapter, as it contains many observations which 

 may help to explain and confirm what I shall offer concerning 

 blights." The letter is as follows : — 



"To Mr. Bradley, &c, 



" Sir, — Upon discoursing with you some time since upon blights 

 upon trees, you seemed to be of opinion that they were the effect 

 of insects brought in vast quantities by the easterly winds, and by 

 lodging upon the plants proper for their nourishment, they produce 

 there the distemper which is known as a " B' .ght or Blast." You 

 was then desirous of what observations I had made concerning pesti- 

 lential distempers subject to mankind, which I believe to proceed 

 from the same cause that produced blights, i.e., from insects. It 

 is a common received opinion, that the plague proceeds from an 



infection in the air, and so undoutedly it does 



He then shows that it cannot be the sole operation of " poisonous 

 vapours from minerals," or such as are found in the Grotto del 

 Cane, or in mines, though " they are plainly more destructive 

 to animal life than any others that have been known, in that they 

 act much quicker upon the spirits of animal bodies than those 

 which are said to occasion the plague and other pestilential diseases. 

 And there is this difference likewise between them, that a body 

 poisoned by the first will not communicate that poison to another, 

 79 



