The South Australian Vine, Fruit, and Vegetable Protection Act 1885 (No. 345) defines 'disease' as meaning-

any of the diseases caused by insects (as defined in this section), and any other disease affecting trees, plants, or vegetables, which the Governor shall from time to time, by Proclamation in the Government Gazette, declare to be a disease within the meaning of this Act.

Section 4 empowers the Governor, by Proclamation, to prohibit, either absolutely or subject to any regulations that he might think proper, the introduction into the Province of any tree or plant or any other thing which, in his opinion, may be likely to introduce any disease or insect into the Province.

By Proclamation dated 14 August 1909, purporting to be made under the said Act, the Governor of South Australia declared certain specified diseases to be diseases within the meaning of the Act, and prohibited, subject to the Regulations under the Act, gazetted on 9 July 1908, the introduction into the State of South Australia of all solanaceous plants or portions thereof.

The Regulations mentioned are scheduled to a Proclamation of the same date, whereby the Governor-

1. prohibits absolutely the introduction into South Australia of any grape vine, or any portion thereof, from any country or State; and
2. prohibits the introduction into South Australia of all other living trees and plants whatever, and any portions thereof, except under and subject to the Regulations in the Schedule.

The Proclamation of 14 August 1909, is apparently intended to prohibit absolutely the introduction of solanaceous plants, and the letter of the Premier of South Australia forwarding the Gazette notice to the Prime Minister confirms this view; though the reference to the Regulations is somewhat puzzling. If the prohibition were only conditional, so that solanaceous plants could be introduced if the Regulations were complied with, it would have no effect at all, because, under the Proclamation of 9 July 1908, that was already the position as regards all plants not absolutely prohibited.

The Director of Quarantine, in reply to a question from the Comptroller-General of Customs whether there was a similar prohibition under the Commonwealth Quarantine Act, minutes the papers as follows:

The 'diseases' named in (1) are all included in the 'diseases of plants' as defined under the Federal Quarantine Act and proclaimed.

The prohibition is wider than that provided for in the Federal Proclamation, as it means the prohibition, not only of potatoes, but also of tomatoes, Cape gooseberries, and also certain medicinal plants. It also means absolute prohibition from all parts of the world, and the question arises as to whether the State Government should not be asked to make the Proclamation explicit as regards its limitation to interstate importations, otherwise, by acquiescing in the Proclamation, we shall be admitting that the State can place additional quarantine restrictions on trade.

The Comptroller-General then minutes the papers to his Minister, as follows:

In this case, the Regulations under the Quarantine Act do not prohibit the introduction of 'all solanaceous plants or parts thereof, and the non-prohibition has been decided upon after full deliberation.

The State Government of South Australia, however, comes in and says they are prohibited.

This prohibition by the State is either ultra or intra vires. If the latter, then the pos-ition is not only that the Federal authority is overridden, but other complications arise, thus-There is no prohibition for Victoria, say; then such plants can be lawfully imported into that State, but, after such importation, cannot be taken across the border into South Australia.

Is such a restriction consonant with the provisions of section 92 of the Constitution, which declares that 'trade, commerce, and intercourse among the States, whether by means of internal carriage or ocean navigation, shall be absolutely free'?

The question raised by this action of the South Australian Government is of con-siderable importance, and the necessity for settlement has been recently brought under Minister's notice, v/We Minister's minute of 31st ultimo.

The Minister for Trade and Customs asks to be advised as to Commonwealth powers under these circumstances. The questions raised in this case are:

1. What are the police powers of a State, in the absence of Federal legislation, as to the exclusion of goods, for the purpose of preventing the introduction of disease?
2. Do the State laws or regulations exceed the scope of their police powers, apart from the question of inconsistency with Federal laws?
3. What is the effect, on State police powers, of Federal legislation covering the whole or a part of the subject-matter?
4. To what extent, if any, are the State police powers superseded or suspended by the Quarantine Act or the Regulations thereunder?

I will deal with these four questions in turn, first premising that the absence of Aus-tralian judicial authority directly in point necessitates reference to American decisions, in which the principles applied to the nearly parallel case of the United States Consti-tution are clearly defined.

1. What are the police powers of a State, in the absence of Federal legislation, as to the exclusion of goods, for the purpose of preventing the introduction of disease?

In the United States, it has been held that the power to regulate interstate com-merce is exclusively with Congress, to the extent that any exercise of State authority which directly regulates interstate commerce is repugnant to the commerce clause of the Constitution: Atlantic Coast Line v. Wharton 207 U.S., at p. 334.

Under the Commonwealth Constitution, it may be doubted whether the commerce clause by itself, section 51 (i), would be held to be exclusive, seeing that the subjects of exclusive legislative power are enumerated in section 52. But the commerce clause is reinforced by section 92, which provides that 'trade, commerce, and intercourse among the States . . . shall be absolutely free'. That section binds the Commonwealth Parliament as well as the State Parliaments; and it cannot therefore mean free from regulation altogether, an interpretation which would nullify the whole legislative power-Commonwealth and State alike-as to the control of interstate commerce. It

must mean free from burdens or obstructions; or, in the words of the Supreme Court of the United States, with reference to the interpretation of an Act of Congress which declared the freedom of certain navigable waters, free from 'political regulations which would hamper the freedom of commerce': Willamette Iron Bridge Co. v. Hatch 125 U.S., at p. 12.

In the United States, again, it is held that, though the States may not regulate in-terstate commerce directly, they may, in the exercise of their police power, and in the absence of Federal legislation covering the subject-matter, legislate to prevent the in-troduction of disease, and provide for the inspection and quarantining of articles of commerce, animals, etc.-with a view to excluding those which are diseased, and admitting those which are healthy, even though interstate commerce may thereby be indirectly affected: Reid v. Colorado 187 U.S. 137; Asbell v. Kansas 209 U.S. 251.

But the State may not by police regulations, whatever their object, unnecessarily or unreasonably burden interstate commerce, the question of necessity and reason-ableness, under all the circumstances, being for the court: Railroad Co. v. Husen 95 U.S., at p. 472; Asbell v. Kansas 209 U.S., at p. 256.

In the Commonwealth Constitution, State inspection laws are impliedly sanctioned by section 112, which defines the power of States to levy charges for their enforcement. Reading sections 51 (i) and 92 together, it would appear that in Australia-whether or not a State Act or regulation would be unconstitutional merely because it was a direct regulation of interstate commerce-it would, as in the United States, be unconsti-tutional if it imposed an unnecessary or unreasonable burden upon interstate commerce.

2. Do the State laws or regulations exceed the scope of their police powers, apart from the question of inconsistency with Federal laws?

The State Act in question is apparently directed to the protection of the State from the introduction of plant diseases and pests. I do not think that any part of it can be said to impose, by itself, an unnecessary burden upon interstate commerce, though regu-lations or proclamations made under it might impose such a burden, and therefore have no validity and afford no legal justification to action taken under them.

I think that an absolute prohibition of certain kinds of plants (healthy and diseased alike) is an unnecessary burden on interstate commerce, and cannot be justified on the ground that it is a precautionary measure against the introduction of disease: Railroad Co. v. Husen 95 U.S. 465; Asbell v. Kansas 209 U.S., at p. 256.

If, as I have assumed, the Proclamation of 14 August 1909, is absolute, I think that it is invalid in toto as being in violation of section 92. If, on the other hand, it is to be construed as conditional only, it is valid unless the conditions can be shown to be un-reasonable, or more than is reasonably necessary for the ostensible purpose. In this re-gard, I think that the courts would be disposed to allow considerable latitude to re-quirements of inspection, certification, term of quarantine, etc.; and that the conditions laid down in the Regulations scheduled to the Proclamation of 9 July 1908 would not be held to be unreasonable.

3. What is the effect, on State police powers, of Federal legislation covering the whole or a part of the subject-matter?

It is held in the United States that where the entire subject of the transportation of (say) livestock from State to State is taken under direct national supervision, and a sys-tem devised by which diseased stock may be excluded from interstate commerce, all

State regulations in respect of such matters and covering the same ground will cease to have any force, whether formally abrogated or not, and such regulations as Congress may lawfully prescribe or authorize will alone control: Reid v. Colorado 187 U.S., at pp. 146-7. This is based on the rule that Federal law is paramount, and State laws in-consistent with it must give way. But if Congress has not covered the whole subject-matter, the State is not excluded; and the repugnance or conflict, in order to supersede State regulation, must be direct and positive, so that the two laws could not be recon-ciled or consistently stand together: Sinnot v. Davenport 22 How., at p. 243; Reid v. Colorado 187 U.S., at pp. 147-8.

And it is not enough that Congress has empowered a Federal authority (e.g. the Inter-State Commerce Commission) to control the whole matter, in the absence of action by that body in pursuance of the power: Missouri Pacific Railway v. Larabee Mills 2\\ U.S., at p. 623.

In my opinion, these principles are entirely applicable to the Commonwealth Constitution.

4. To what extent, if any, are the State police powers superseded or suspended by the Quarantine Act or the Regulations thereunder?

As regards importation from other countries, the Commonwealth has, in my opinion, covered the whole ground by Part V of the Quarantine Act 1908, which establishes a complete system of inspection and quarantine. In my opinion, any State Regulations to the same end are now superseded; and the Proclamation of 14 August 1909, if construed to include importation from other countries, is void in toto. I think, however, that in accordance with the rule in D'Emden v. Pedder 1 C.L.R. 91, the gen-eral words of the Proclamation would be construed as limited to introduction from other States.

As regards interstate commerce, I am of opinion that the Commonwealth has not covered the whole ground. It is true that the Parliament has, by section 13, empowered the Governor-General by Proclamation to-

(g)prohibit the removal of any plants or parts of plants from any part of the Com-monwealth in which any disease affecting plants exists to any part of the Common-wealth in which the disease does not exist;

(h)declare any part of the Commonwealth in which a disease affecting plants exists to be a quarantine area;

(i)declare that any plants in any quarantine area, or in any part of the Common-

wealth in which any disease affecting plants exists, shall be subject to quarantine.

But, in the first place, these provisions do not cover the whole ground of interstate quarantine. They are, in fact, only reserve powers, the exercise of which is expressly limited by sub-section (2) to cases in which the Governor-General is satisfied that their exercise is necessary to prevent the spread of a disease across a State boundary. And, in the second place, these powers have not in fact been exercised.

Construed, therefore, as limited to introduction from other States, I do not think that the Proclamation (assuming it to be otherwise valid) is invalid on the ground of in-consistency with the Quarantine Act 1908.⁽¹⁾

[Vol. 7, p. 261]

(1) This opinion was published in Commonwealth of Australia, Pari. Papers 1909, Vol. II, p. 2265.