Abetter understanding of the mode of action of vitamin $\mathrm{K}$ is made possible by the use of an anticoagulant. One such naturally occurring antagonist of vitamin $\mathrm{K}$ is known as Dicumarol. The discovery of the anti-coagulating property of Dicumarol took place when it was established that consumption of improperly cured sweet clover hay caused cattle to develop the so-called "sweet clover disease" which is attributable to a serious alternation in the coagulability of the blood that, in turn, often result in fatal haemorrhage.