SECRETARY'S REPORT. 91 



weather was hot and the animals were more than usually excited. 

 In the worst cases I have attributed it not only to the milk of the 

 animals in heat, but aggravated by that of those which became 

 sympathetically excited, over exercised and feverish in consequence 

 of the cows which were in heat. Milk at such times is feverish, 

 and akin to a mass of putridity, and not unfrequently a feted or 

 very offensive odor is emitted from the whey and curd if used»for 

 cheese-making. Such milk will no more produce solid curd than 

 it would give health and nutriment to a calf when taken into its 

 stomach. When made into cheese, there is a tendency to undue 

 fermentation and rapid decomposition, and its character is precisely 

 similar to cheese made with putrid rennet. But such extreme 

 cases are only occasional." Serious trouble in cheese-making, I 

 am informed, has occasionally been experienced by dairymen in 

 Maine from the same cause. 



It is well known that milk will often suddenly develop into a 

 state of acidity during thunder storms, but why it should thus be- 

 come sour has long been shrouded in mystery. Some have con- 

 founded this with the effect of jarring or jostling, or that produced 

 by vibratory motion of the air, as by beating of drums. It is now 

 well understood to be due to the presence of ozone which is gen- 

 erated in the atmosphere by electrical action. Ozone is simply 

 oxygen gas in a changed, or as it is called, allotropic condition. 

 It possesses some very curious and wonderful properties, and 

 among them intense oxidizing* or acidifying powers. The remedy 



* A thin sheet of pure silver, if exposed for a few minutes to the action of ozone, 

 will be thoroughly oxidized and fall into powder, which is an oxide or true rust. A 

 piece of tainted meat so exposed quickly loses all offensive odor. Ozone undoubtedly 

 plays a most important part in the operations of nature, and probably also in the 

 functions of the animal economy. Comparatively little is yet known of it ; and the 

 phenomena attending what is now known as " allotropism " are so strange and 

 wonderful as absolutely to stagger all previous philosophy. Although wholly un- 

 connected with the subject of cheese-making, I cannot refrain from inserting here a 

 few remarks from one of Prof. Faraday's lectures : " There was a time, and that 

 not long ago, when it was held amongst the fundamental doctrines of chemistry that 

 the same body always manifested the same chemical qualities, excepting only such 

 variations as might be due to the three conditions of solid, liquid and gas. This was 

 held to be a canon of chemical philosophy, as distinguished from alchemy ; and a 

 belief in the possibility of transmutation was held to be impossible, because at vari- 

 ance with this fundamental tenet. But we are now conversant with many examples 

 of the contrary ; and, strange to say, no less than four of the non-metallic elements, 

 namely, oxygen, sulphur, phosphorus and carbon, are subject to this modification. 

 The train of speculation which this contemplation awakens within us is extraordinary. 



