Mr. T. Hopkins's Observations on Malaria. 107 



shores being either rocky, or well drained and under cultiva- 

 tion, and consequently dry. They are also nearer to the 

 Atlantic Ocean, and therefore cooler in the summer than the 

 eastern coast. These two causes may be sufficient to account 

 for the difference which is found on the eastern and western 

 coasts of this country. But I have been informed by Dr. 

 Briggs of Ambleside, formerly resident in Liverpool, that in 

 his younger days autumnal agues were common on the low 

 grounds of Lancashire, paiticularly in that part called the 

 Fylde country, and that they occasionally prevail at present. 

 Their diminution may be attributed to the better drainage 

 of the country, which has converted it from a comparative 

 marsh to dry tillage land. That the clouds of mountainous 

 regions do not produce fevers may arise from their low tem- 

 perature. And as to the fact that south-west and south winds 

 produce fevers in Flanders, while on a sea wind coming which 

 covers the country with fogs the fevers disappear, this may 

 only prove that the sea wind being a cold one, the reduction 

 of the temperature caused the fever to cease. The Doctor 

 seems to think that there is great force in the remark " that 

 if a fog alone could produce fever water I'tself must be the 

 poison:" but the argument may not, as we shall presently 

 see, turn on the water in the atmosphere as water, but as 

 steam or elastic vapour. And it may be found that when 

 there is a certain quantity of steam in the atmosphere at a 

 high temperature, disease may be a consequence, notwith- 

 standing that water is wholesome in a liquid state. Dr. Mac- 

 cuUoch's opinions respecting the cause of malaria are at vari- 

 ance with numerous and well ascertained facts. This pest 

 is found on sea borders and islands, as on the coasts of 

 Italy and Africa, on the small Maldive islands in the Indian 

 Ocean, in the West Indian islands, even in Barbadoes, which 

 pushes out east a considerable way into the Atlantic ; it is also 

 found at sea at great distances from land, and beyond the 

 reach of effluvia from vegetable putrefaction. In the valuable 

 statistical report of sickness and mortality among the troops 

 in the West Indies, recently laid before the House of Com- 

 mons, it is said, when speaking of the hypothesis of vegetable 

 exhalation producing malaria, — " Were this hypothesis cor- 

 rect, we might expect that British Guiana would, from its 

 proximity to this cause of disease, be most subject to its ope- 

 ration, and consequently the most unhealthy, and that the 

 colonies further to the north, being least exposed to it, would 

 enjoy the greatest degree of salubrity. The result of our in- 

 vestigations into the comparative mortality in each colony 

 shows however that their relative salubrity is by no means 



