Vol. XXn. No. 7.] 



POPULAE SCIEE"OE l^rEWS. 



103 



J^ome, ifarnt, anD aarUnt. 



CANNED GOODS. 



The use of canned goods is now universal, 

 and the emptj' tin can is found scattered over 

 tlie entire country, from the summits of the 

 Roeiiy Mountains to the sea-beaches of the 

 Atlantic and Pacific coasts. It is said in 

 the far West that the first article to enter a 

 newl}- opened-up country- is a barrel of whis- 

 key, and the second a missionar}' ; but even 

 a Western cow-bo}- or prospector cannot live 

 on whiskey alone, and the canned provisions 

 form a convenient and cheap means of suppl}- 

 ing the pioneers of civilization with food in 

 regions where without them it would be almost 

 impossible to travel. 



The philosophy' of preserving food from 

 decomposition is very simple. After the cans 

 are filled, the}' are heated to the boiling-point 

 of water for a sufficient length of time to 

 destroy all the microbes, or germs of decom- 

 position and putrefaction which may be pres- 

 ent. The can is then hermetically sealed, 

 and, if the operation has been properly con- 

 ducted, will preserve its contents indefinitely. 



The question of the healthfulness of food 

 preserved in this manner has been a subject 

 of much discussion. It may become danger- 

 ous in two ways, — from a partial decompo- 

 sition of the contents of tiie can, or a metallic 

 contamination, from the tin or solder from 

 which the can is made. Animal products 

 particularly, in some stages of decomi)osition, 

 are likely to develop certain exceedingly 

 l)oisonous alkaloids, known as ptomaines. 

 Tlie well-known tyrotoxicon which is occasion- 

 ally formed in milk and cheese, and causes 

 serious illness, is an example of this class of 

 bodies ; and it is probable tliat the rare eases 

 of illness reported from the use of canned 

 meats are duo to their presence. The danger 

 from this cause, however, is so slight, tiiat it 

 ma}- be practical!}' considered as non-existent, 

 as, with the modern improvements introduced 

 into the canning process, and the care taken 

 by reputable firms to secure fresh and whole- 

 some materials, there is little likelihood of 

 such accidents occurring. In addition, the 

 slightest taint of decomposition is so very 

 noticeable in canned materials, that it is 

 hardly possible to overlook it. 



There remains, then, the possibility of 

 metallic contamination, and this is a matter 

 of considerable importance. Of course, it 

 could be entirely avoided by using glass or 

 porcelain vessels ; but the expense and fragil- 

 ity of these prevent their use in the majority 

 of cases. The tin plates from which the 

 metallic cans are made are formed from 

 sheets of iron covered with pure tin. A 

 cheaper grade, called terne plate, is covered 

 with an alloy of tin and lead, and the solder 

 with which they are joined together always 

 contains a certain proportion of lead. Again : 

 in the process of soldering, the metal must 

 l)e cleaned with a corrosive liquid, and chlo- 

 ride of zinc is usually selected for the purpose. 



There is, of course, a possibility of contami- 

 nation from any of these sources ; but it is 

 gratifying to know that it is a possibility that 

 is rarely or never realized. 



As far as we know, the cheap terne plate 

 is never used for making the cans, and the 

 action of the food upon metallic tin is not 

 appreciable. Even if there should be any 

 action, it must be remembered that the salts 

 of tin, while unwholesome and injurious, are 

 not nearly as poisonous as those of lead. As 

 regards the use of solder containing lead, 

 practical experience has shown that it is 

 rarely acted upon in any way by the con- 

 tents of the can. The principal canning 

 firms now use a process by which the solder 

 is applied on the outside of the can, so that 

 little or none of it is brought in contact with 

 the contents. As to the introduction of sol- 

 dering fluid, itis always unnecessary, and could 

 only happen through the most reckless care- 

 lessness. 



In an article on this subject, the American 

 Grocer makes the following statements : — 



So far as our knowledge and experience go, 

 there is not a case on record of sickness or death 

 arising from "poison accidentally introduced" 

 during any process connected with the preparation 

 of hermetically sealed food, nor has the report of 

 a case showing the presence of any poisonous 

 substance used in soldering been authenticated. 



Professor Edward S. Wood, M D., who ex- 

 amined the canned vegetables for the Massachu- 

 setts State Board of Health, did not report a single 

 case of any thing detrimental found in American 

 caimed goods ; but, out of thirty-two samples of 

 imported French vegetables, reported twenty-two 

 showing the presence of copper used for coloring- 

 purposes: but as regards this practice even such 

 eminent French authorities as Pasteur sanction 

 it as harmless, although American packers of 

 vegetables do not use it at all. 



While, therefore, we would not recommend 

 the use of canned provisions when fresh ones 

 can be obtained, we think the weight of tes- 

 timony is very much in their favor as whole- 

 some and harmless articles of food. In these, 

 as in every thing else, there are different 

 grades of quality and price ; but the slightly 

 greater cost of the goods prepared by well- 

 known firms of undoubted reliabilit}' is more 

 than counterbalanced by their assured purity 

 and healthfulness. 



ARTIFICIAL FLAVORS. 



In the wonderful laboratory of the growing 

 plant, by processes of which we know almost 

 nothing, the atoms of carbon, hydrogen, 

 oxygen, and nitrogen are made to group 

 themselves into compounds which give to 

 our vegetables and fruits the delicious flavors 

 characteristic of them. In most cases this 

 flavoring principle is so small in quantity, and 

 so complex in its nature, that the chemist is 

 unable to satisfactorily determine its compo- 

 sition ; and it is probable that few of the 

 natural flavors are simple chemical substances, 

 but rather mixtures of different organic salts, 

 ethers, and alcohols. 



The flavoring principle of the majority of 



fruits can be directly extracted and preserved 

 by simple means, forming extracts for flavor- 

 ing food which are as unobjectionable as they 

 are agreeable. Unfortunately it happens, 

 however, that many of these flavors can be 

 imitated by various chemicals, which, while 

 they are much cheaper than the natural prod- 

 uct, are unwholesome and even dangerous. 

 As a general thing, the artificial flavors are 

 much coarser and ranker than the natural 

 ones, and lack entirely the peculiar fruity taste 

 distinctive of the latter. 



The greater part of the artificial essences 

 belong to the class of compounds known as 

 ethers, or, more strictly speaking, salts of an 

 organic acid and base. The artificial essence 

 pineapple, for instance, is composed of ethyl 

 butyrate, or a combination of butyric acid (the 

 acid of rancid butter) and a radical known as 

 ethyl (CjHg), which is also present in common 

 alcohol. By combining the ethyl with pelar- 

 gonic acid, we obtain an ether with a flavor 

 resembling that of the quince. Ethyl caprate 

 is sometimes known as oenanthic ether, and is 

 one of the flavoring substances found in old 

 wine. 



Another radical, amyl (CjHjj), is also the 

 base of several artificial flavors. Amyl alcohol 

 CjHji-O-H is the poisonous fusel-oil found in 

 the poorer grades of whiskey. Amyl acetate 

 forms the well-known essence of Jargonelle 

 pear, while amyl valerianate is a very good 

 imitation of the flavoring matter of the apple. 

 Amyl caprate is found in Hungarian wine. 



The natural flavors of the peach, plum, 

 almond, etc., are due to nitrogenous bodies 

 containing cyanogen, the base of the poisonous 

 prussic acid. With the exception of the 

 almond, these flavors are not often imitated; 

 but a substance made from coal-tar, known as 

 nitro-benzol, has an intensely strong taste and 

 odor of bitter almonds, and, under the name 

 of oil of mirbane, is employed to a consider- 

 able extent as a perfume and flavoring extract. 

 It is, however, a powerful poison, and should 

 never be added to food. 



Vanilla, as is well known, is the product of 

 a Mexican plant. When pure it is perfectly 

 wholesome, but it has been said to sometimes 

 undergo a spontaneous decomposition which 

 renders it dangerous. This, however, is not 

 fully confirmed, and the bad effects observed 

 may have been due to other causes. It con- 

 tains a substance commonly known as vanillin, 

 but chemists distinguish it by the brief appel- 

 lation methylprotocatechuic aldehyde. This is 

 now made artificially in large quantities from 

 the gum of spruce and other coniferous trees. 



There are many other organic bodies which 

 possess very characteristic odors, although not 

 commonly used for flavoring purposes. For- 

 mate of ethyl is sometimes used to give an 

 agreeable taste to rum. Acetic ether, or acetate 

 of ethyl, has the fragrance of cider, while acet- 

 acetic ether, C2H(C2H30)HO.O C^H^, has the 

 odor of new-mown hay. Ethyl nitrite has a 

 pleasant apple-like smell ; while amyl nitrite 

 has an odor peculiar to itself, which produces 

 such remarkable physiological effects, that it is 



