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the low fat content of the milk of others. Daily I’

analyses of the mixed milk of a large dairy have shownthat the fat content of the mixed milks is seldombelow 3 per cent. A dairyman with a small herd ofcows in certain states of lactation and nutrition mayeasily have a milk with less than 3 per cent. of fatand be liable to prosecution. It is impossible to

safeguard this dairyman under the present standards.Even if his milk be tested directly, it may happenthat on that particular day the milk passes thestandard. Only by further analysis of the milk-i.e., by the determination of lactose and protein-canthis dairyman be protected, for it is unlikely thatprotein, fat, and carbohydrate will all be below thestandard at the same time. Protein may be high andcarbohydrate low and vice versa ; fat may be highand carbohydrate low. If all the constituents arebelow the limits of variation at the same time, thecase is then more clearly one for prosecution.Milk is one of the few foods which contain all

three vitamins, its content in these accessory foodfactors depending entirely upon the food of the cowor other animal. The anti-scorbutic or C vitaminhas been definitely shown to be more abundant inthe milk of grass-fed cows than that of stall-fed cows.Summer milk is a better anti-scorbutic than wintermilk. The same holds for the fat-soluble A vitamin.The amount of factor A in milk may be closelyconnected with the greater prevalence of rickets inspring (after winter feeding). The absence of theanti-neuritic or B factor in milk has been most clearlydemonstrated in certain human milk. Children havebeen cured of beri-beri if the mother has been suppliedwith food containing B vitamin. All the threevitamins in milk are derived from the food of theanimal and are not produced by the animal. Further,there is no connexion between chemical compositionof milk and vitamin content. A milk of high fatcontent mav be low in content of factor A. Milkfrom a cow on dried food does not contain C factor.

HUMAN REMAINS AS HISTORICAL DOCUMENTS.

THE opinion was at one time prevalent that wecould learn no more of the origin of the Britishpeople than writers of antiquity had chosen to tellus. From the report on the hTuseum of the RoyalCollege of Surgeons of England just issued by itsconservator, Sir Arthur Keith, we learn that theprospect of a reliable history of the kind of peoplewho have inhabited this country for many thousandsof years past continues to improve. Only those whoare familiar with the methods and industrv of modernarchaeologists are aware of the exactness with whichancient graves and their contents can be dated.All the experience gathered by archaeologists inEgypt, Mesopotamia, France, Italy, Germany,’Scandinavia, and Britain is being pooled, with theresult that the British archaeologist obtains a clueto the dating of the various funereal customs whichhe comes across in the course of his explorations.From the present report, as from those of previousyeara, we note that the College of Surgeons’ Museumis becoming a mausoleum " for such human remainsas serve as historical documents." To be worthpreserving human remains must be excavated withthe skill that knows how to look for and how topreserve evidence of date. Anglo-Saxon cemeteriesand graveyards of the Roman period are not un-common, but very few have been explored with skill.From a Roman cemetery excavated on the propertyof Mrs. Clifford at Barnswood, near Gloucester,a large sample of west-country people, of the thirdcentury A.D., has just been obtained.We learn further from the present report that

the preservation of human remains of known date,which began from purely academic reasons, is likelyto throw light on many problems--obviously onthe prevalence of caries of the teeth, pyorrhoea,muscularity and stature of the people, but also onmore obscure conditions, such as contraction of the

palate and prevalence of conditions affecting thegrowth of bones. In the opinion of Sir Arthur Keithcontraction of the palate, now affecting 40 per cent.of the modern population of English cities, is of

comparatively recent origin. We are glad to notethat the Scientific and Industrial Research Councilhas recognised the national value of the great collectionof human skulls and other remains which has beenbuilt up by the Council of the College, and has givena grant to pay a research worker to compile a newand reasoned catalogue of this section of the Museum.Among other points of interest in the report maybe mentioned the gift of the Onodi collection of nosespecimens, and the further additions to the War Officecollection of specimens illustrating war woundsand their sequelae. We note, too, that the annualexhibition of recent additions to the Museum, formerlygiven in July, is henceforth to take place in October.

THE TUBERCLE BACILLUS IN PERIPHERALBLOOD.

THE tubercle bacillus is always being hunted insome corner of the human body. Every channel ofinfection is explored and every secretion and excretionexamined with much expenditure of carbol-fuchsinand counterstain ; and yet there are still wide gapsin our knowledge of the march of the infectingorganism from the point of entrance to the ultimateclinical focus of disease. Possibly the key to this94

regional survey" is to be found in the circulatingblood. Each successive era of experimentation seemsto fasten the responsibility more definitely upon theblood, and thereby to bring tuberculosis more intoline with the clinical pathology of other infectivediseases. First bone and joint tuberculosis, thengenito-urinary, and finally pulmonary tuberculosisbecome the field of our inquiry. But in spite of veryreasonable grounds for hope bacteriological demon-stration of the bacillus in the blood is hard to comeby, except in those cases of miliary tuberculosis whichare in a class apart. Shortly before the war mildexcitement was caused in tuberculosis circles by thereports of Rosenberg Kurashiga and others, whofound bacilli in 100 per cent. of cases in the blood ofboth early and advanced cases of phthisis. Thenfollowed disillusionment ; others could not verify theresults. Kahn 2 showed that numerous causes oferror arose in artefacts ; and Fraenkel disposed ofthe 100 per cent. positive results by making inocula-tions of peripheral blood into guinea-pigs and findingonly two positive cases out of 25 ; other workersobtained similar results. In an original article onthis subject recently published by Distaso,4 theseresults are summarised. Sixteen different investi-gations by various workers on 928 cases yielded 84positive findings. Distaso, in addition, gives theresults of an interesting series of experiments madeby himself into the various stages of pulmonary andsurgical tuberculosis (febrile and afebrile), most ofwhich experiments yielded negative findings. A groupof cases of afebrile pulmonary tuberculosis, however,gave a surprising number of positive results-9 outof 13. This group is difficult to reconcile with thefindings in febrile groups, and it is unfortunate thatDist,aso was unable to go over this work again withre-inoculation experiments, especially as he seems tohave been content with the: demonstration of giantcells in his positive guinea-pigs and did not obtaintubercle bacilli. The latest report of the Robert Koch-Stiftung, recently received, contains an article byE. Rumpf,5 of Hamburg, which is an exhaustiveinquiry into the whole subject. Microscopic, cul-

tural, and inoculation tests were carried out by theauthor, and a series of controls made upon normalpeople. Growth on media did not take place, whilst

1 Zeitschs. f. Tub., 1911, xvii., 347.2 Munch. med. Woch., 1913, lx., 345.

3 Deutsch. med. Woch., 1913, xxxix., 737.4 Tubercle, 1921, ii., 251.

5 Veröffentlichungen der Robert Koch-Stiftung, Bd. ii.,H. 3, p. 163.

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in the animal inoculation experiments only a smallpercentage (5-7 and 8 percent. in two different series)were positive. The author concludes that the acid-fast bacilli so frequently found, microscopically, incentrifuged blood by other workers are not virulenttubercle bacilli whatever else they may be.And at this point we must be content for the

moment to leave the question. Tubercle bacilli havebeen sought for in many hundreds of blood specimenswithdrawn from the vein in the usual way, but withthe use of the guinea-pig inoculation test only ratherless than 10 per cent. of positive findings have beenrecorded. We now require to know whether thesepositive cases represent a class of case separate anddistinct from all other cases of tuberculosis, or whetherthev indicate a phase in the clinical history of alltuberculous cases-a phase during which bacilli aredischarged into the blood stream and there rapidlydestroyed. ____

DETACHMENT OF THE RETINA.

THE problem of detached retina is one of themost difficult in ophthalmology. Neither as toits pathology nor its treatment is there anygeneral agreement, and in spite of isolated instancesof cure, to which many ophthalmic surgeons can

testify, the sad fact remains that in the vastmajority of cases an eye in which the retinabecomes detached inevitably goes blind. At anyrate, cases of cure are sufficiently rare to justify thepublication of any case such as that reported inanother column by Mr. Foster Moore. At the sametime the word " cure " can hardly be applied to acase which, apparently, has only been under observa-tion for a few weeks since the reattachment of theretina was observed. A committee of the Ophthalmo-logical Society, reporting on the subject in 1916,1decided to consider a case " cured " when the retinahad gone back into position and stayed there for sixmonths. To some of the committee even this periodseemed too short, and the report expressed the opinionthat it must certainly be regarded as the irreducibleminimum. Cases, indeed, are common in which afterrest in bed or some form of operative treatment theextent of a detachment becomes much diminished, andoccasionally -it may even disappear altogether, onlyto relapse as soon as the patient resumes a normalactive life. The number of published and un-

published cases of " cures

" collected by this con-i-

mittee was 85. It should be added, however, thatnot every uncured case of detached retina goes onrapidly to complete blindness. Some eyes in whichthere is still a demonstrable detachment retain evenfor vears a certain amount of useful vision.

There are types of cases in which the prognosis ismuch less unfavourable. In cases following a blow,in which the cause of the detachment is an effusionof blood beneath the retina, the prognosis is favour-able. The same is true of another class of cases towhich Mr. Moore calls special attention—viz., detach-ment occurring with renal retinitis. and especially inpregnancy cases. In discussing the pathology andcure of detached retina these " symptomatic " casesare generally excluded, and attention is directed solelyto the so-called " simple " cases, which, after all,constitute the great majority. As to their pathologytwo facts are known with certainty. The attachmentof the retina proper to its pigmentary epithelium layeris so loose that the space between them is always apotential cavity, which in cases of detachment becomesan actual one containing fluid. The second fact isthat the majority of these cases, but by no meansthe large majority, occur in myopic eyes-i.e., ineyes in which the retina has become abnormallystretched, and the vitreous cavity abnormallyenlarged. Further, in a small proportion of thesecases rents or holes in the detached retina are

observed ophthahnoscopically. Again, in a few casesbands in the vitreous are seen, apparently attached

1 Trans. Ophthal. Soc., 1916, vol. xxxvi.

to the separated part of the retina. Starting fromthese facts, different theories of the causation of thedisease have been held. Graefe held that it was dueto exudation into the inter-retinal space from diseasedchoroidal vessels. Deutschmann maintained thatpractically all cases are due to the traction of vitreousbands on the retina causing rents. Raehlmann putforward a theory of an abnormal osmotic pressureresulting in an excessive current of fluid from beforebackwards into the inter-retinal space. Now, non&

of these theories carry us much further towards asuccessful method of treatment. Deutschmann, in-deed, himself claimed a large percentage of cures byhis method of dividing the vitreous bands, but hisclaims entirely lack confirmation. Of the methodsof treatment now generally in vogue the first placeshould undoubtedly be given to rest in bed. Inrecent cases, indeed, this by itself diminishes theextent of detachment and temporarily improves thevisual acuity. In exceptional cases it appears thata detachment can be really cured by this measurealone. as in two cases reported by Mr. J. B. Lawfordin 1915.2 It must be added, however, that there areother exceptional cases in which a detachment appearsto have been cured without any treatment whatever.The second place in treatment will generally be givento evacuation of the subretinal fluid, either by punc-ture with a Graefe knife or by the cautery. Theunfavourable comment made by Mr. Moore uponthis operative procedure is rather surprising.With regard to subconjunctival injections they havegenerally been employed as an adjunct in the way oftreatment. and their action has been attributedsomewhat loosely to counter-irritation. It hasbeen found experimentally that an injection beneaththe conjunctiva is followed by a marked increase inthe albuminous contents of the aqueous. Whetheror not Mr. Moore’s case is an instance of cure fromrest in bed or from subconjunctival injections, or

whether it is a permanent cure at all, time andfurther experience will show. We are glad to reportthe case.

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FRIENDLY SPAS.

Ix the early days of the present month of fineweather. Sir Henry Lunn arranged for a group of20 representative British medical men to visit Aix-les-Bains and a number of the Swiss watering places.France and Switzerland are justly proud of thefacilities which they are able to offer for hydrotherapyand aerotherapy, under conditions of great naturalbeauty, and the grave depression which these spasare undergoing is due to political and economiccauses. and not in any sense to individual failure.The state of the money market has deprived the spasof whole sections of their usual clientele, while theSwiss themselves are largely seeking recreative holidayin adjacent countries where the exchange is in theirfavour. It is not unnatural, therefore, that Aix-les-Bains, Ragaz, and the Engadin should look to aninflux of patients from English-speaking countries toretrieve their fortunes, the more so as it was Englishcustom which set going their prosperity a generationor more ago. Of the warmth of the reception whichawaits them there no doubt can exist ; the hospitalitylavished on the British medical visitors was evidentlysomething more than a laudable desire to makeknown certain attractive therapeutic wares ; it wasan earnest of the valuable team-work of hotelier, spaphysician, and skilled attendant which is at thecommand of every patient and which has broughtthe practice of balneology to a level behind which itsscientific basis sadly lags. The immediate future islikely to see this made good, for at the principalbaths in the Upper and Lower Engadin scientificwork is being done by men of professorial rank inconnexion with the universities of Berne and Zurich,and at Aix-les-Bains the local medical society iskeenly alive to the need of showing that medicinal

2 Trans. Ophthal. Soc., 1915, vol. xxxv.