Sept. 1st, 1887.] 



SCIENTIFIC NEWS. 



165 



should become in some way or another the vehicle of contagium, 

 as has been proved lo be the case in a number of epidemic out- 

 breaks. These epidemics, known as milk scarlatina, milk diph- 

 theria, and, lie might also add, milk typhoid, have this in 

 common, that almost simultaneous^, or, at any rate, within a 

 short time, in a number of houses having no direct communica- 

 tion, by person or otherwise, with one another, there occur, 

 sometimes singly, sometimes in batches, as it were, cases of ill- 

 ness — scarlet fever, diphtheria, or typhoid fever, as the case may 

 be ; and it was this peculiar character which pointed to a con- 

 dition which must have been common to all these households. 

 On closer examination it was, indeed, found that all these house- 

 holds had this, and only this, in common, that they were all 

 supplied with milk coming from the same source — that is to say, 

 from the same dairyman. Other houses, supplied with milk 

 from a different source, escaped ; and, further, it was shown 

 that, as soon as the consumption of the suspected milk ceased, 

 the epidemic, as such, came to an end, except, of course, the 

 cases due to secondary infection from person to person. 



The Medical Department of the Local Government Board 

 have had for years past their attention fixed on these milk 

 epidemics, and in the reports of the medical officer many of these 

 are described with great detail ; amongst these Dr. Ballard's re- 

 port in 1870 on Enteric Fever in Islington, Dr. Buchanan's on 

 Scarlet Fever in South Kensington in 1875, and Mr. Power's on 

 Scarlet Fever in St. Giles's and St. Pancras in 1882, are es- 

 pecially to be referred to. Mr. Ernest Hart has tabulated all 

 the outbreaks of milk epidemics which were investigated before 

 1881 in vol. iv. of the " 'Transactions of the International Medical 

 Congress for 1881." Now, analysing these outbreaks as far as 

 they refer to scarlet fever, there are several of them where the 

 assumption that the milk consumed acquired the power of in- 

 fection by contamination from a human source cannot be ex- 

 cluded. This infection, if proven, would stand on the same 

 footing as if due to contagion from person to person ; for it is 

 clear, whether the contagium is conveyed from one person to 

 another by air, food, drink, or otherwise, it always remains con- 

 tagion from person to person. Now, in many of the cases of 

 epidemics tabulated by Mr. Hart, and recorded by subsequent 

 observers — i.e., after 1S81 — this mode of milk contamination 

 cannot be excluded, as I said before ; but comparing the dates 

 when the milk was supposed to have become so contaminated 

 with the dates when the milk has actually produced infection, it 

 will be found that a certain discrepancy exists, and, as will be 

 shown later, another mode of infection — viz., from a person 

 affected with scarlatina to the cow, and through the cow to the 

 milk, and then to human beings — cannot be excluded either. 

 There are other epidemics recorded in these tables in which the 

 mode of infection of the milk is not ascertained, and in a third 

 set the milk acquired infective power in some way or another, 

 but certainly not from a human source. 



Examples of each kind were given, and the lecturer stated 

 that the Medical Department of the Local Government Board 

 have from these facts drawn the conclusion that " distrust must 

 be placed on the universally accepted explanation that milk 

 receives infective properties directly by human agencies," and 

 further that " the question of risk from specific fouling of milk 

 by particular cows suffering, whether recognised or not, from 

 specific disease was seen to be arising." This view received 

 striking confirmation and proof by a report of an outbreak of 

 scarlet fever that occurred at the end of 1885 and the beginning 

 of 1886 in the north of London, which was investigated by Mr. 

 Power. This report is published //; c.xtcn^o in the Report of the 

 medical officer of the Local Government Board for 1886, and in 

 this it was shown that at this Hendon farm there existed certain 

 cows affected with a communicable disease which, in many 

 points of its pathology, bears a great resemblance to human 

 scarlatina ; further, that the milk of these cows gave scarlet 

 fever to human beings ; and, lastly, that a particular microbe 

 was obtained from these cows, which in calves produced a 

 similar disease to the disease of those cows. 



In order to complete the evidence thus far obtained, it was 

 necessary to prove that scarlet fever in man is due to the pre- 

 sence and multiplication in the blood and tissues of the same 

 micrococcus, and that this microbe, if obtained from human scarlet 

 fever, produces in the cow the same disease as is produced by the 

 micrococcus of the Hendon cows. Now, this proof has been 

 satisfactorily given. In the first place, it has been shown that 

 in the blood and tissues of persons affected with scarlet fever 



there occurs the same micrococcus as was present in the cow, 

 both being identical in microscopical and in cultural characters. 

 In the second place, it was found that the action of this microbe 

 on animals is exactly the same as the micrococcus found in the 

 Hendon cows. Calves and mice after inoculation or feeding 

 with a trace of the growth of both sets of micrococci, become 

 affected with cutaneous and visceral disease similar to human 

 scarlet fever ; in calves the disease is of the same mild type as 

 in the Hendon cows. Further, it was shown that from the blood 

 and the tissues of these animals infected with one or the other 

 set of cultivations the same micrococcus was recovered. This 

 microbe, micrococcus scarlatincF, is the cause of human scarlet 

 fever ; further, it produces in bovine animals a disease identical 

 with the Hendon disease and human scarlet fever, and conse- 

 quently, while the cow is susceptible to infection with human 

 scarlet fever, it can, in its turn, be the source of contagium for 

 the human species, as was no doubt the case in the milk 

 epidemic from the Hendon farm. 



The lecturer then came to the question — How is the spread 

 of scarlet fever by milk to be controlled and checked? This 

 question, he said, resolves itself into three parts. First, pre- 

 vention of infection of the cow by man, directly or indirectly; 

 second, prevention of infection of the cow by the cow ; and, 

 third, destruction of the contagium of the milk of such cows. 

 As regards the first, all those rules which have been laid down 

 to prevent infection of one human being from another, of milk 

 or any dairy utensil, by contact or otherwise, with a person 

 suffering from scarlet fever or coming from an infected house, 

 also apply here ; and this part of the subject comes under the 

 general aspect of the proper sanitary management of dairies 

 which is acted upon in all well-managed dairies. As regards 

 the second, this is obviously more important and more difficult 

 of carrying out. The disease in the cow, being of a mild 

 character, is easily overlooked. The disease in the skin of the 

 cow may be present and slight, or may be absent in its more 

 conspicuous manifestation, whereas the visceral disease is of so 

 mild a character that it requires an expert to diagnose it. The 

 third question, as to the destruction of the contagium in the 

 milk, he was glad to say, is very easily carried out. He had 

 found that heating milk up to 85° C, or 185° Fah. — that is, con- 

 siderably under the boiling point — is perfectly sufficient to com- 

 pletely destroy the vitality of the microbe of scarlet fever. 



PHYSICAL SOCIETY OF BERLIN. 



AT a recent meeting, held under the presidency of Prof. Du 

 Bois-Reymond, Dr. Sommer spoke of the methods for deter- 

 mining the specific weight of bodies, with special reference to the 

 method by weighing them in water. After having discussed the 

 earlier methods and experiments of Marck and Lepiney, he gave 

 an account of the methods he had himself employed in order to 

 do away with the influence which the capillary forces at the 

 surface of the water exert on the wire by which the solid is 

 suspended. He surrounds the wire at the point where it enters 

 the water with a glass tube 5 mm. in width, in which is placed 

 one drop of a mixture of equal parts of olive-oil and benzene. 

 From the lower end of the wire in the distilled water he hangs a 

 tiny tray on which two cubes of quartz are placed. Using a wire 

 o-l mm. in diameter, which he finds gives a result as accurate as 

 weighing in air, he determines the weight of these quartz cubes 

 in water, then pushes one of the cubes off the tray by means of 

 a platinum wire which had been previously submerged, and 

 weighs again. He then pushes the second cube off the tray and 

 weighs a third time. These three weighings, taken in con- 

 junction with the weight of the tray and cubes in air, yield an 

 exactitude which up to the present time has either not been 

 attained at all by hydrostatic methods or only by a laborious 

 and roundabout process. The exactness of this method of deter- 

 mining the specific weight of (]uartz cubes surpasses that 

 obtained by the use of a piknometer. The President gave an 

 account of a communication which had been made by Siemens 

 at the last meeting of the Akademie der 'Wissenschalt. A steel 

 tube 10 cm. long, with perfectly smooth external and internal 

 surfaces and extremely uniform bore, and whose walls are 

 apparently of perfectly equal thickness at all points, was pre- 

 pared by the following method, patented by Miinnermann in 

 Bemscheid. Two rollers, slightly conical towards their lower 

 ends, are made to rotate in the same direction near each other ; 

 a red-hot cylinder of steel is then brought between these cylinders. 



