I am grateful to Gerald Gordon for pointing out that
(“Special jurors” were persons (a) paying cess in the county, city, town, or place from which the jury was to be taken, upon £100 of valued rent; or (b) paying assessed taxes to the Crown on a house of the yearly rent of £30 sterling: see the Jury Trials (Scotland) Act 1895 and Renton and Brown’s Criminal Procedure (2nd edn by GR Thomson, 1928) 71). The distinction between special and “common” jurors was abolished by the Juries Act 1949.)
The reduction in the size of the jury did not apply to trials for treason or murder, or in any High Court case where the court, on the application of one of the parties, directed that the “gravity of the matters in issue” required a jury of fifteen.
Similar provisions were made for
“A jury, which in pursuance of the last foregoing subsection, consists of seven persons, shall not be entitled to return a verdict by a majority, unless five of their number are in favour of such a verdict.”
Note that this says “shall not be entitled to return a verdict”, not “shall not convict”. Applied literally, this would have introduced into
“When the Act was put into operation, it became evident that this subsection was not very clearly worded as it did not specifically provide for the conditions under which a verdict of acquittal in a criminal case may be returned. The view was, however, taken that the section merely meant that, in the case of a verdict of guilty by a majority, the majority must be at least five to two; i.e. that five at least of the seven jurors must be in favour of a verdict of guilty, and that, if this condition is not satisfied, there must be a verdict of acquittal.” (Mackay v HM Advocate 1944 JC 153 at 156)
The question of the appropriate size of the jury was reconsidered by the Thomson Committee. In its second report, it recommended that criminal juries should be reduced to twelve in number, with seven votes required for conviction (an even split resulted in an acquittal). There was one dissent:
“Professor Gordon, however, was strongly of opinion that, whatever the size of the jury, there should be a 2:1 majority for guilty… The basis of his opinion is that a simple majority for guilty is too narrow and that an accused should not be convicted where more than one-third of the jury are not sufficiently satisfied of his guilt. The remainder of us are content to accept conviction on a majority of less than two-thirds. We consider that insistence on the weighted majority is unnecessary in view of the other safeguards which our system provides for the protection of the innocent…” (Criminal Procedure in Scotland (Second Report) (Cmnd 6218, 1975) para 51.12).