Studies were carried out on 5 sheep 2-4 years old of about 40 kg in weight successively in summer and autumn. The experiment conditions and the method were the same as in part one of this paper. The most effective inhibitors of methanogenesis used included also fatty acids such as linoleic and cis-oleic acid, some saturated fatty acids as; behenic and stearic, chloral hydrate, sodium sulphite and chloroform. Various changes in the composition of the rumen gases and in their ratios were caused by the individual inhibitors. Moreover, an increased dose of the inhibitor always resulted in increased inhibition of methane production, which was the highest in sheep fed on a bulky food. The observations also showed that the application route of the inhibitors had no effect on their action. The methane production inhibitors used did not cause any appetite disturbances in the experimental sheep and not show any toxic effect.