138 

process. Even so the danger of tuberculosis, etc. has 
been greatly reduced, for dosage of infection is an 
essential element in the result. The temperature 
prescribed in the recent Order of the Ministry of Health 
is not less than 145° F. and not more than 150° F. 
for at least half an hour, the milk to be immediately 
cooled to a temperature of not more than 55° F. It 
is also laid down that any sample of pasteurised milk 
taken before delivery to the consumer shall not con- 
tain more than 30,000 bacteria per c.c. nor any bacillus 
coli in one-tenth of a cubic centimetre. 
It is unfortunate that, in the somewhat hesitating 
and tentative regulations of the Ministry of Health, 
it has not been regarded as advisable to regulate the 
conditions of commercial pasteurisation, which is 
practised on a large scale without any special certificate 
being asked for by the producer. It is probable 
that at the present time most of the milk coming 
into London is pasteurised, though not always satis- 
factorily. In American cities such pasteurisation is 
subject to rigid supervision, an automatic gauge of 
the temperature of pasteurisation being kept for 
official inspection: and the system now inaugurated 
in England, in which it will be possible for vendors 
to pay for a certificate of permission to sell ‘‘pasteur- 
ised ” milk, while their neighbours are selling pasteur- 
ised or partially pasteurised milk without such a 
certificate and without disclosure of the fact that the 
milk has been treated by heat, is obviously a system 
which should not continue. The uncertified and un- 
declared pasteurisation has real possibilities of mischief ; 
for it leads the unsuspecting purchaser to subject 
the milk to repeated heating to its detriment. Such 
doubly-heatéd milk is liable to produce scurvy and 
rickets. This naturally leads to the consideration of 
the drawbacks to pasteurisation of milk. The evi- 
dence goes to show that pasteurisation as defined 
above, followed by rapid cooling, does not spoil the 
milk. Such milk, like dried milk, has not been shown 
to produce scurvy: and any fear on this point is 
averted by the use of fruit juice in small quantities. 
Although the vitamin-content of milk treated on the 
‘holder’ system has not been adequately investi- 
gated, experimental observations quoted in the October 
issue of the Scottish Journal of Agriculture show that 
there need be little apprehension on this head, especi- 
ally if the precautionary use of fruit juice is adopted. 
The admirable results of feeding infants on dried milk 
confirm this opinion. 
The general enforcement of pasteurisation of milk 
is called for in the public interest, and there can be 
little doubt that step by step this will come into 
operation. It is the most practical method of State 
NO. 2779, VOL. III | 
NATURE 
some of the milk may escape too soon from the heating | regulation; and it secures immediate safety against 
| dangers at present associated with its consumption. 
[FEBRUARY 3, 1923 
serious risks of infection when carried out satisfactorily. 
For many years efforts to improve the sanitary con- 
ditions of the farm and the cow-byre have been 
made, but with results which are quite incommen-— 
surate with the expense involved. By dirt tests, 
bacterial counts, insistence on cooling of the milk at 
the farm, and allied measures, both the wholesale 
purchaser of the farmer’s milk and the sanitary 
authority can do much to increase its cleanliness ; 
but pasteurisation is the essential safeguard in the 
public interest. Attacks on pasteurised milk are not 
justified scientifically, and they imply, if successful, a 
continuance of the supply of infective milk, with the 





Pasteurisation is already enforced in a considerable 
number of American cities, and we would welcome 
action on the part of the British Government which 
would permit large local authorities in this country 
to aid the milk industry and to safeguard the public 
health by enforcing the pasteurisation under satis- 
factory conditions of the local milk supply. 
The pasteurisation of milk supplies carries with 
it the distribution of milk in sterilised sealed bottles, 
which is an important safeguard against domestic 
contamination, a chief source under present conditions — 
of mischief. ; 
The Ministry of Health has issued regulations also as 
to superior qualities of milk, which may be described 
as Certified, Grade A or Grade A (tuberculin tested). — 
Grade A milk is described in the official notice 
circulated with these regulations as “superior to the - 
ordinary milk of the country and reasonably safe 
under all ordinary circumstances.” Evidently certi-— 
fication of such milk must be made with fear and 
trembling. According to the schedule of conditions 
imposed, the cows have not been proved to be 
free from tuberculosis by the tuberculin test, the 
chief test imposed being a trimestrial examination of — 
the herd by a veterinary surgeon, who orders the 
exclusion of any animal “showing evidence of any 
disease which is likely to affect the milk injuriously.” 
American experience has shown that even with tuber- — 
culin testing, it is necessary to pasteurise the Grade A 
milk supplied for children’s hospitals: and the above 
certificate for Grade A milk cannot be regarded as 
conferring anything approximating to the security 
for the consumer which efficient pasteurisation pro- 
vides. The above-quoted definition conduces to 
furious thought. We must regard the “ ordinary 
milk of the country ”’—the milk with which the vast 
majority of children are supplied—as not “ reason- 
ably safe.” If so, and it is so, why does the Ministry 
of Health stop short of a simple regulation requiring 
