INFLUENZA IN HORSES. 231 



is as follows : September, by day 1.58, by niglit 2.65 ; October, by clay, 1.G4, by night 

 1.96; November, 3.70 by day, and 4.06 by night ; December to the 16th instant, by day, 

 1.91, and by night 3.16. The excess of ozouo for November, 1872, over November, 1871, 

 is .90 by day and 3.11 by night ; and for corresponding periods of December, 1872; over 

 December, i87T, is, by day, 3.65, and by night, 3.50. 

 The disease is rapidly closing np birsiness here, apparentlj' for want of raw material. 

 Very respectfully, yours, &c., 



R. C. KEDZIE. 

 Pi'ofessor Law. 



In view of this extraordinary excess of ozone at Lansing during- the 

 influenza period, it is much to be regretted that comparative observa- 

 tions are not obtainable from all parts of the continent. That the ozone 

 has been generally in excess is possible, and that it lays the system 

 open to the attack of the specific poison is not at all unreasonable, but 

 it cannot be looked upon as the one and essential cause of the disease. 

 If it were, why has the soliped been the only victim, since man has 

 often shared the calamity on previous occasions 1 And, above all, why 

 has the disease in every instance pursued a regular progiTss over the 

 land in keepiug with the facilities for rapid transit ? The proofs of 

 contagion furnished below entirely destroy the doctrine of the pathoge- 

 nisis of the disease by a general excess of ozone. If ozone is in excess 

 everywhere, and has any connection with the disease, it must either be 

 a result of the propagation of the i")oison, or only an accessory cause, 

 operating by weakening the system and laying it ojjen to the attack of 

 a poison which would otherwise remain powerless. 



Electricity. — No reports of the state of the atmospheric electricity are 

 to hand, but, like ozone, if potent at all, it could only bo so in producing 

 the first case or cases. It might be conceived of as affecting the nutrition 

 of the animal body, so as to produce from its elements a morbid poison 

 capable of indefinite reproduction, and of communicating the disease 

 from animal to animal. But to conceive of the same electrical condi- 

 tion spreading by slow and steadily advancing steps over the continent 

 for the space of three months, in all the varied phases of altitude and 

 the opposite ; of rain, snow, and fair weather ; of clouds and sunshine ; 

 of atmospheric moisture and dryness 5 of storm and calm, in city and 

 country, on the inland, table-land, and valley, and on the sea-shore, is 

 not in keeping with what we know of this agency. 



According to Peltier, the electricity of the earth is always negative, 

 and that of a dry atmosphere positive. Gay-Lussac and Biot found 

 that the greater the altitude they attained in a balloon, the stronger 

 was the positive electricity. Becquerel and Breschit found no evidence 

 of positive electricity in the six feet nearest to the surface of the earth, 

 in close-sheltered places, in the court-yards of houses, in the streets 

 of cities, or in narrow valleys. In a calm, pure atmosphere the elec- 

 tricity is uniformly disseminated, and therefore little marked, but with 

 a lowering of temperature and the condensation of the contained 

 watery vapor into more or less dense clouds, the electricity concen- 

 trates itself around the wateiy particles and leads to extensive dis- 

 turbances of the equilibrium. Tlie action of the earth renders these 

 clouds more negative in their upper than in their lower parts. 

 Water falling in rain is as often positive as negative ; falling as snow, it 

 is positive four times in every five. Slight rains do not modify the at- 

 mospheric electricity, while heavy rains increase it positively or nega- 

 tively. The approach of a hailstorm determines great inequalities in 

 the electric tension of the air; strong winds also seriously disturb the 

 equilibrium. It has been stated that rains occurring during souti, 

 southeast, and southwest winds are mostly negative, while those with 



