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THE BROAD TAPEWORM IN NORTH AMERICA.
780 from time to time), by restricting to registered chemists the power to sell, by prohibiting sales to persons unknown or not vouched for, and by requiring entries of sales to be made in a Poisons Book. No doubt it was deemed right that a dangerous poison should be sold only by a qualified chemist, who would use his skill and judgment in warning the purchaser of the nature and quality of the drug supplied. In 1908, however, came the important relaxation which has enabled ironmongers, storekeepers, and other unqualified persons all over the country to sell arsenic freely. Section 2 of the Poisons and Pharmacy Act of 1908 declared that the restrictions of the 1868 Act were not to apply to poisonous substances containing arsenic, tobacco, or tobacco alkaloids sold for .agricultural and horticultural purposes, provided that the seller was duly licensed by the local authority and that he observed the prescribed regulations. The obtaining of a licence seems to be a mere formality ; the renewal of a licence is an easier process still. Regulations of 1909 require that sheep-dip and weedkiller must be kept in a separate drawer or closed xeceptacle, apart from other goods, and must not be sold at the same counter as food for human consumption. Regulations of 1920 (replacing earlier requirements) add that the poisonous substance must not be ..sold except in enclosed vessels or receptacles as received from the manufacturers, secured from leakage and labelled with the name and purpose of the substance, the word " Poison," and the seller’s name and address. ’These rules are excellent so far as they go ; but the law places no restriction on the storage or possession of arsenic in this form, nor is there any prohibition on sale to persons under age. Thus, as our legal contemporary observes, a chemist may not sell half an ounce of powdered arsenic to a youth under age who wants it for killing rats ; but a corn-dealer may sell a gallon of liquid arsenic, or a pound of powdered arsenic made up into a packet and called " weed-killer," to any boy of 16 whom he knows, and who says he wants it for killing weeds in his father’s garden. Further, it appears that even unlicensed persons are often found offering weed-killer for sale, either in ignorance of the law, or in the mistaken belief that any tradesman mav sell these goods if they are supplied in the original package sent out by the The time seems ripe for reconsidering manufacturer. whether arsenical preparations are so indispensable in the garden, or on the farm, as to justify the exception made in their favour in 1908, and also whether the .conditions of their supply and use are not, in any case, too free from control. It may be said that the public .its weary of incessant restrictions, and that a would-be murderer will always manage, somehow, to equip himself for his nefarious purpose. The present laxness of the law,however, is in marked contrast with the retraints imposed by statutes in 1920 upon the possession of firearms and of dangerous drugs. It would be instructive to have statistics of the proportion of poisoning cases in which the obtaining of arsenic in the form of sheep-dip or weed-killer has " facilitated - the commission of the crime." THE BROAD TAPEWORM IN NORTH AMERICA.
’’ THEpast year has added considerably to what is known of the distribution and hygienic significance of the plerocercoid of Diphyllobothrium latum in the region of the great lakes of North America.1 This
stage is by
no
means
restricted to the
Michigan
Infected fish have been reported by T. Vergeer2 from Lakes Winnipeg, Manitoba, Nipigon, .and Winnipegosis, from Lac la Biche, and from the Lesser Slave Lake ; while H. E. Essex3 has proved that Cyclops brevispinosus, C. prasinus, and Diaptoknus Peninsula.
first larval hosts. It must that man is not the only ,definitive host of this cestode. There is, for example,
o;’c(jonensis act locally be
as
emphasised, however,
See THE LANCET, 1928, ii., 337. 2 Canad. Med. Assoc. Jour., 1928, xix., 692. 3 Jour. Parasitol., 1927, xiv., 106. 1
a moderate infection of nsh in the smaller Canadian lakes far from towns. In these parts, when Indians or white men while fishing for trout catch wall-eyes and great northern pike-fisli constantly infected with the plerocercoids-such unwanted fish are fed raw to dogs, of which every man seems to have at least one, and some a pack ; and the dogs are readily infected, as many as 19 parasites having been found in one animal.44 Moreover, the broad tapeworm has been reported from the fox, Vulpes fulvus, and from the domestic cat. The grey wolf, lynx, mink, marten, racoon, and otter feed on fish, and Vergeer has readily infected the cinnamon bear, which in the spawning season has been known to scoop as many as 20 fish out of the water on to the bank before starting his meal. Man is thus but one of a number of definitive hosts used by D. latum, and that he cannot be the main one is shown by Vergeer’s calculationthat the United States imports yearly from Canada upwards of 6,000,000 plerocercoids hidden in fish, while only about 200 cases of human infection haveever been reported from the United States. The risk to man can hardly be considered great enough to justify that ruining of an important industry, with great loss to concerns dependent on it, which would follow the exclusion of Canadian fish from the United States. Careful disposal of human sewage is evidently insufficient to prevent infection of fish, but man is readily and fully protected by the cooking of his fish food, and woman will lose her preponderant tendency to infection when the Jewess gives up her habit of tasting raw fish to test her skill in flavouring it.
PECTOSE AND ITS ALLIES. substances, known as the pectins or pectic compounds, which occur in apples, pears, and other fruits as well as in such roots as turnips and carrots, form a valuable stand-by for the jam maker, and this circumstance has brought them within the purview of the Food Investigation Board. -.Uis. M. H. Branfoot (nee Carre), the author of a study6 made has herself contributed on behalf of the Board, greatly to the clarifying of our knowledge of these obscure substances to which over 300 workers have directed their attention during the last 100 years. The essential difficulty of studying the pectins is that they are uncrystallisable, they form no welldefined compounds, they are difficult to purify, and chemically they seem to lead nowhere ; and this in spite of the fact that such skilled workers as Regnault, Cross and Bevan, Winogradsky, and other well-known botanists and chemists have sought to clear up their relations. Braconnot seems to have been the first to realise (in 1825) that these bodies existed, but Fremy first described (in 1840) the parent substance, pectose, as an alcohol- and water-insoluble body associated with cellulose in the cell-walls of plants, but chemically very unlike cellulose. Later workers found pectose difficult to isolate in an unchanged state ; acids and alkalis may dissolve it with production of pectin and pectic acid, but they also change it. Pectose. indeed, appears from the work of Fellenberg and Carre to be formed by the union of cellulose with pectin; acid hydrolysis resolves it again into its constituents. Ehrlich concluded that the natural pectin of plants may be conceived as a complex anhydro-arabinosegalactose - methoxy - tetra - galacturonic acid. The replacement of a variable number of methoxygroups by cellulose may be supposed to confer insolubility on the complex, which would be hydrolysable to varying degrees by acids and alkalis, or by other hydrolysing agents such as the natural enzymes found in plants. Having regard to the difficulty of ensuring that one is dealing with a chemical individual, it is not surprising that such THE class of
4 Jour. Amer. Med. Assoc., 1929, xcii., 607. 5 Jour. Infect. Dis., 1929, xliv., 1. 6 A Critical and Historical Study of the Pectic Substances of Plants. H.M. Stationery Office. Pp. 154. 3s. 6d.
’’ THEpast year has added considerably to what is known of the distribution and hygienic significance of the plerocercoid of Diphyllobothrium latum in the region of the great lakes of North America.1 This
stage is by
no
means
restricted to the
Michigan
Infected fish have been reported by T. Vergeer2 from Lakes Winnipeg, Manitoba, Nipigon, .and Winnipegosis, from Lac la Biche, and from the Lesser Slave Lake ; while H. E. Essex3 has proved that Cyclops brevispinosus, C. prasinus, and Diaptoknus Peninsula.
first larval hosts. It must that man is not the only ,definitive host of this cestode. There is, for example,
o;’c(jonensis act locally be
as
emphasised, however,
See THE LANCET, 1928, ii., 337. 2 Canad. Med. Assoc. Jour., 1928, xix., 692. 3 Jour. Parasitol., 1927, xiv., 106. 1
a moderate infection of nsh in the smaller Canadian lakes far from towns. In these parts, when Indians or white men while fishing for trout catch wall-eyes and great northern pike-fisli constantly infected with the plerocercoids-such unwanted fish are fed raw to dogs, of which every man seems to have at least one, and some a pack ; and the dogs are readily infected, as many as 19 parasites having been found in one animal.44 Moreover, the broad tapeworm has been reported from the fox, Vulpes fulvus, and from the domestic cat. The grey wolf, lynx, mink, marten, racoon, and otter feed on fish, and Vergeer has readily infected the cinnamon bear, which in the spawning season has been known to scoop as many as 20 fish out of the water on to the bank before starting his meal. Man is thus but one of a number of definitive hosts used by D. latum, and that he cannot be the main one is shown by Vergeer’s calculationthat the United States imports yearly from Canada upwards of 6,000,000 plerocercoids hidden in fish, while only about 200 cases of human infection haveever been reported from the United States. The risk to man can hardly be considered great enough to justify that ruining of an important industry, with great loss to concerns dependent on it, which would follow the exclusion of Canadian fish from the United States. Careful disposal of human sewage is evidently insufficient to prevent infection of fish, but man is readily and fully protected by the cooking of his fish food, and woman will lose her preponderant tendency to infection when the Jewess gives up her habit of tasting raw fish to test her skill in flavouring it.
PECTOSE AND ITS ALLIES. substances, known as the pectins or pectic compounds, which occur in apples, pears, and other fruits as well as in such roots as turnips and carrots, form a valuable stand-by for the jam maker, and this circumstance has brought them within the purview of the Food Investigation Board. -.Uis. M. H. Branfoot (nee Carre), the author of a study6 made has herself contributed on behalf of the Board, greatly to the clarifying of our knowledge of these obscure substances to which over 300 workers have directed their attention during the last 100 years. The essential difficulty of studying the pectins is that they are uncrystallisable, they form no welldefined compounds, they are difficult to purify, and chemically they seem to lead nowhere ; and this in spite of the fact that such skilled workers as Regnault, Cross and Bevan, Winogradsky, and other well-known botanists and chemists have sought to clear up their relations. Braconnot seems to have been the first to realise (in 1825) that these bodies existed, but Fremy first described (in 1840) the parent substance, pectose, as an alcohol- and water-insoluble body associated with cellulose in the cell-walls of plants, but chemically very unlike cellulose. Later workers found pectose difficult to isolate in an unchanged state ; acids and alkalis may dissolve it with production of pectin and pectic acid, but they also change it. Pectose. indeed, appears from the work of Fellenberg and Carre to be formed by the union of cellulose with pectin; acid hydrolysis resolves it again into its constituents. Ehrlich concluded that the natural pectin of plants may be conceived as a complex anhydro-arabinosegalactose - methoxy - tetra - galacturonic acid. The replacement of a variable number of methoxygroups by cellulose may be supposed to confer insolubility on the complex, which would be hydrolysable to varying degrees by acids and alkalis, or by other hydrolysing agents such as the natural enzymes found in plants. Having regard to the difficulty of ensuring that one is dealing with a chemical individual, it is not surprising that such THE class of
4 Jour. Amer. Med. Assoc., 1929, xcii., 607. 5 Jour. Infect. Dis., 1929, xliv., 1. 6 A Critical and Historical Study of the Pectic Substances of Plants. H.M. Stationery Office. Pp. 154. 3s. 6d.