396 DISEASES CLA&S IV. 1. 4. 4. 



quantity of heat in spring, than they had undergone in the lat- 

 ter part of autumn, which may however be ascribed to their 

 previous torpid state, and consequent accumulation of sensorial 

 power or irritability; as explained in Botanic Garden, Part II. 

 Canto I. 1. S22. note. Other circumstances, which counte- 

 nance the idea, that vegetation is affected by solar gravitation, as 

 well as by heat, may be observed in the ripening of the seeds of 

 plants both in those countries where the summers are short, 

 3d in those where they are long. And by some flowers closing 

 their bells at noon, or soon after; and hence seem to sleep 

 rather at solar diurnal periods, than from the influence of cold, 

 or the deficiency of light. 



4. Orgasmatis venerei periodus. The venereal orgasm of birds 

 and quadrupeds commences or returns about the vernal or au- 

 tumnal equinoxes, and thence seems in respect to their great 

 periods to be governed by solar influence. But if this orgasm 

 be disappointed of its object, it is said to recur at about monthly 

 periods, as observed in mares and bitches, in this respect re- 

 sembling the female catamenia. See Sect. XXXVI. 2. 3. and 

 Sect. XVI. 13. 



5. Brachii concussio electrica. The movement of the arm, 

 even of a paralytic patient, when an electric shock is passed 

 through it, is owing to the stimulus of the excess of electricity. 

 When a piece of zinc and another of silver, each about the size 

 of a crown-piece, are placed one under the upper lip, and the 

 other on the tongue, so as the outer edges may be brought into 

 contact, there is an appearance of light in the eyes, as often as 

 the outer edges of these metals are brought into contact or sepa- 

 rated; which is another instance of the stimulus of the passage 

 of electric shocks through the fibres of the organs of sense, as 

 well as through the muscular fibres. See Sect. XII. 1.1. But 

 in its natural state electricity seems only to act as an influence 

 on animal and vegetable bodies; of the salutary or injurious ef- 

 fects of which we have yet no precise knowledge. 



Yet if regular journals were kept of the variations of atmo- 

 spheric electricity, it is probable some discoveries of its influence 

 on our system might in time be discovered. For this purpose a 

 machine on the principle of Mr. Bennet's electric doubler might 

 be applied to the pendulum of a clock, so as to manifest and 

 even to record the daily or hourly variations of aerial electricity. 

 Which has already been executed, and applied to the pendu- 

 lum of a Dutch wooden clock, by Mr. Bennet, curate of Wirks- 

 worth in Derbyshire. 



Besides the variations of the degree or kind of atmospheric 

 electricity, some animals, and some men, seem to possess a greater 



