This is another of the many appeals which have come to this Court involving the construction of that vexing piece of legislation, viz. the Commonwealth Employees' Compensation Act. In an earlier case reference has been made to the difficulty which has been created by the drafting device of defining "disease" as including, in the absence of a contrary intention, "any physical or mental ailment, disorder, defect or morbid condition, whether of sudden or gradual development, and also includes the aggravation, acceleration or recurrence of a pre-existing disease" when it is only in s. 10 of the operative provisions of the Act that the word "disease" is to be found. In s. 10 (1) the word "disease" appears four times and not always is the definition appropriate. Having considered the section carefully again I adhere to what I said in The Commonwealth v. Bourne [1] . There I said: - "When used in s. 10 (1) (a) and in s. 10 (1) (b) the words of extension just quoted would seem to be inappropriate; if suffering from a disease causes the incapacity of or a disease causes the death of a worker, it is the disease at the stage of development that it has reached and not its aggravation, acceleration or recurrence that brings about incapacity or death. In the last part of s. 10 (1) where the word "disease" is used twice the incorporation of the definition would seem to require that it is the contraction of the disease either for the first time or as a recurrence, or its aggravation or acceleration that is to be treated as personal injury by accident arising out of or in the course of the employee's employment if the contraction, recurrence, aggravation or acceleration was due to the nature of the employment, and incapacity or death was caused by the disease in the sense already stated". Despite the argument to the contrary, it would, I think, be to depart from what was said by Dixon C.J. and Fullagar J. as well as by myself in Bourne's Case [1] to disregard the definition of disease in the construction of s. 10 (1). The Chief Justice said: - "The word "nature" is a wide as well as a vague word and one must be careful not to narrow its application or attempt to reduce it to too much precision. But it does seem to refer to a connexion between the "disease" in the defined sense and the description of employment in virtue of its tendencies, incidents or characteristics. The investigation of sales tax cases appears to me to have nothing in its nature to accelerate vascular and cardiac degeneration" [2] . Fullagar J. said: - "It was not shown, nor, I should imagine, could it have been shown, that a characteristic or distinctive feature of employment as a taxation investigating officer was a tendency to cause arterial sclerosis or myocardial degeneration, or to aggravate or accelerate an existing condition of arterial sclerosis or myocardial degeneration. Such a tendency, so far as appears, was no more part of the nature of Mr. Bourne's employment than of the nature of any other responsible employment. That employment was not, so far as I can see, of such a nature as to expose Mr. Bourne to a special risk of contracting any particular disease or of suffering an aggravation or acceleration of any particular disease and s. 10 applies, in my opinion, only to cases in which there is such a special risk" [3] . The citation from the Chief Justice includes a reference to "disease" in the defined sense and Fullagar J. uses the words of the definition "aggravation" and "acceleration". See too The Commonwealth v. Thompson [4] , per Dixon C.J. [5] and Windeyer J. [6] where in each case the definition of "disease" has been regarded as applicable to s. 10 (1).